NOTE MILLER IN A CASHLESS SOCIETY: FINANCIAL SURVEILLANCE AND THE FOURTH AMENDMENT Matt Wostbrock* In United States v. Miller, the Supreme Court declared that the Fourth Amendment does not protect Americans’ bank records because there is no reasonable expectation of privacy in the data. More recently, while limiting the third-party doctrine in Carpenter v. United States, the Court expressly left Mil- ler standing by distinguishing the checks and deposit slips in Miller from the cell site location information in Carpenter. The Carpenter majority described the bank records in Mil- ler as containing “limited types of personal information,” but the continued use of that distinction relies on an outdated pic- ture of financial technology and consumer habits. Financial records have evolved significantly since Miller was decided in 1976, and ever-increasing reporting and retention require- ments have created massive financial databases. In an increas- ingly cashless society, financial records can reveal intimate and comprehensive information about nearly every American. Still, this Note recognizes that courts are unlikely to find them worthy of constitutional protection, and it does not argue that all searches of them should be subject to a warrant require- ment. This Note instead aims to highlight our vast financial surveillance infrastructure, consider its costs and benefits, and advocate for Congressional narrowing of the procedures for ac- cess to and use of financial records by government agents. *J.D. Candidate 2024, Columbia Law School; B.S. 2018, University of South Carolina. My sincere thanks to Professor Kathryn Judge for her guidance and insights, and to the Columbia Business Law Review staff for their thoughtful feedback in preparing this Note for publication. 1016 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 I. Introduction .................................................................... 1016 II. .................................................................................. 1021 A. Bank Secrecy Act and Financial Surveillance .... 1021 B. The Fourth Amendment’s Evolution and Exclusion of Financial Records .......................................... 1027 C. Miller after Carpenter ......................................... 1032 III. .................................................................................. 1035 A. Changes in Financial Technology and Consumer Practices ............................................................. 1035 1. Technology and Consumer Practices ............ 1035 2. Carpenter’s Growing Inconsistencies ............ 1041 B. The Law Enforcement Tradeoff .......................... 1045 C. “No Single Rubric” will Resolve these Issues in the Courts ................................................................ 1049 1. Differing Originalist Conceptions of the Fourth Amendment ...................................... 1050 2. Mosaic Theory and Judicial Line Drawing ... 1054 IV. .................................................................................. 1058 A. Congressional Checks on Financial Records Searches ............................................................. 1058 1. Time Constraints ........................................... 1058 2. Suppression as a Remedy under the RFPA .. 1061 3. Reforming Mandatory Reporting .................. 1063 V. Conclusion ..................................................................... 1064 I. INTRODUCTION If these people had done bad things they ought to be ashamed of themselves and he couldn’t pity them, and if they hadn’t done them there was no need of making such a rumpus about other people knowing.1 1 HENRY JAMES, THE REVERBERATOR 209 (1888). No. 2] MILLER IN A CASHLESS SOCIETY 1017 In the time it will take you to read this Introduction,2 about twenty-one Suspicious Activity Reports (SARs) will be filed.3 SARs are reports from financial institutions to the federal gov- ernment that are mandatory whenever those institutions wit- ness illegal or unexplainable activity.4 The forms contain de- tailed information about the reported individual or entity, including identifying information, any transaction details, and an explanation of the suspicion.5 Law enforcement across the country can search these records without a warrant,6 and may subpoena the financial institution for additional infor- mation on the reported party.7 The SAR process is only one piece of the larger financial surveillance infrastructure in the United States. Even with- out a SAR, if law enforcement believes that information would be relevant to an investigation, they may subpoena an insti- tution for financial records.8 Financial institutions are also re- quired by statute to retain customer information for years.9 2 Brett Nelson, Do You Read Fast Enough To Be Successful?, FORBES (June 4, 2012), https://www.forbes.com/sites/brettnelson/2012/06/04/do-you- read-fast-enough-to-be-successful/?sh=4a6f280462e7s [https://perma.cc/F9DL-UAPP]. The average adult reads at 300 words per minute. If you are one of the few people who will read this student Note, you may be faster. 3 3,809,824 SARs were filed in 2023. Suspicious Activity Report Statis- tics, FINCEN, https://www.fincen.gov/reports/sar-stats [https://perma.cc/H4ZJ-H9LR] (choose “2023” from dropdown; then choose “All” for Industry Type; then generate search). 4 31 C.F.R. § 1020.320. 5 12 C.F.R. § 21.11. See also FINANCIAL CRIMES ENFORCEMENT NET- WORK, FINCEN SUSPICIOUS ACTIVITY REPORT (FINCEN SAR) ELECTRONIC FILING INSTRUCTIONS (Oct. 2012), https://www.fincen.gov/sites/de- fault/files/shared/FinCEN%20SAR%20ElectronicFilingInstructions- %20Stand%20Alone%20doc.pdf [https://perma.cc/8MSA-2E4J]. 6 FINCEN, FACT SHEET: THE FINCEN PORTAL, https://www.fin- cen.gov/sites/default/files/shared/Facts_FinCENPortal.pdf [https://perma.cc/RS4J-GC8P]; FinCEN, FACT SHEET: FINCEN QUERY, https://www.fincen.gov/sites/de- fault/files/shared/Facts_FinCENQuery.pdf [https://perma.cc/D93C-BPR8]. 7 12 U.S.C. § 3405. 8 Id. 9 31 C.F.R. §§ 1010.400–440. 1018 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 These steps are all done below a probable cause standard, and without an independent arbiter to challenge whether the gov- ernment has proven that the information is relevant to an on- going investigation. Between 2019 and 2022, the Department of Homeland Security used this power to demand all border state transaction records over $500 from two large money transmitters.10 This bulk surveillance program collected over six million transaction records and allowed unrestricted ac- cess to the data for hundreds of law enforcement agencies.11 Over the last 50 years, the government has built an exten- sive system of mandated recordkeeping and reporting by fi- nancial institutions, and increasingly many other businesses. With this information, they undoubtedly conduct legitimate investigations,12 but critics contend that constitutional rights have been discarded in the process.13 In United States v. Mil- ler, the Supreme Court declared that the then-fledgling Bank Secrecy Act did not violate Americans’ constitutional rights because people have no reasonable expectation of privacy in their bank records.14 More recently, while limiting the third- party doctrine in Carpenter v. United States, the Court ex- pressly left Miller standing by distinguishing the bank checks 10 Matthew Guariglia, Here’s How ICE Illegally Obtained Bulk Finan- cial Records from Western Union, ELEC. FRONTIER FOUND.: DEEPLINKS BLOG (Mar. 10, 2022), https://www.eff.org/deeplinks/2022/03/heres-how-ice-ille- gally-obtained-bulk-financial-records-western-union [https://perma.cc/8Z4Z-PEWD]. 11 Id.; While some surveilled parties have sued the government and the money transmitters in response, they are unlikely to prevail as there is no constitutional protection of one’s financial data, see infra Section II.B, and statutory rights are also limited. See infra Sections II.A, IV.A. As of this writing, defendants have filed motions to dismiss the complaint. Sequeira v. U.S. Dep’t of Homeland Sec., 4:22-cv-07996 (N.D. Cal. Oct. 26, 2023). 12 FinCEN Recognizes Law Enforcement Cases Significantly Impacted by Bank Secrecy Act Filings, FINCEN (May 19, 2020), https://www.fin- cen.gov/news/news-releases/fincen-recognizes-law-enforcement-cases-sig- nificantly-impacted-bank-secrecy-act [https://perma.cc/4EJG-BHVU]. 13 Michael Gentithes, The End of Miller’s Time: How Sensitivity Can Categorize Third-Party Data After Carpenter, 53 GA. L. REV. 1039 (2019). 14 United States v. Miller, 425 U.S. 435, 442 (1976). No. 2] MILLER IN A CASHLESS SOCIETY 1019 and deposit slips in Miller from the cell phone location data in Carpenter.15 But financial technology has evolved greatly since Miller was decided in 1976, and in the past decade American society has increasingly relied on non-cash financial transactions.16 The Covid-19 pandemic17 and the proliferation of FinTech have only increased that trend.18 Nearly every transaction we make is recorded by credit card companies, banks, merchants, and other actors.19 These transactions reveal intimate details of our lives: where we travel, what we buy, who we associate with, what organizations we support, and more. The changes have altered financial records’ connection to traditional Fourth Amendment values, and corresponding privacy 15 Carpenter v. United States, 138 S. Ct. 2206, 2219 (2018). 16 See generally EMILY CUBIDES & SHAUN O’BRIEN, 2022 FINDINGS FROM THE DIARY OF CONSUMER PAYMENT CHOICE, FED. RSRV. BANK OF S.F. (May 5, 2022), https://www.frbsf.org/wp-content/uploads/sites/7/2022-Findings- from-the-Diary-of-Consumer-Payment-Choice-FINAL.pdf [https://perma.cc/VEG7-R87H]. 17 WORLD BANK, COVID-19 Drives Global Surge in Use of Digital Pay- ments (June 29, 2022), https://www.worldbank.org/en/news/press-re- lease/2022/06/29/covid-19-drives-global-surge-in-use-of-digital-payments [https://perma.cc/32EJ-MXFN]; Kristi Egerth, Cash Is No Longer King in Times of COVID-19, DELOITTE, https://www2.deloitte.com/ch/en/pages/con- sumer-industrial-products/articles/cash-is-no-longer-king-in-times-of- covid19.html [https://perma.cc/7297-EMJA]; Anneke Kosse & Robert Sze- mere, Covid-19 Accelerated the Digitalisation of Payments, BANK FOR INT’L SETTLEMENTS (Dec. 9, 2021), https://www.bis.org/statistics/pay- ment_stats/commentary2112.htm/ [https://perma.cc/EZ7Y-2XF4]. 18 Ben Cohen, Wait, When Did Everyone Start Using Apple Pay?, WALL ST. J. (Aug. 18, 2022), https://www.wsj.com/articles/apple-pay-iphone-wal- let-apps-11660780139?st=l1fbf12jpmgfj9m [https://perma.cc/Y8MC-L3X4]. Tech companies, like Apple, plan for people to “replace their physical wallet” and complete all transactions from their phones. Apple Pay is now accepted by 90% of retailers and used by around 75% of iPhone owners. Other com- panies have similar retail products that are pushing consumers away from cash. Id. 19 See DAVID W. PERIKINS, CONG. RSCH. SERV., R45716, LONG LIVE CASH: THE POTENTIAL DECLINE OF CASH USAGE AND RELATED IMPLICATIONS 11 (May 10, 2019). https://www.wsj.com/articles/apple-pay-iphone-wallet-apps-11660780139?st=l1fbf12jpmgfj9m https://www.wsj.com/articles/apple-pay-iphone-wallet-apps-11660780139?st=l1fbf12jpmgfj9m 1020 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 protections are needed to keep the equilibrium.20 Given this financial surveillance structure and our progression to a cash- less society, we should reconsider the carte blanche law en- forcement has in accessing Americans’ financial infor- mation.21 However, a delicate balance must be struck, as “a probable cause standard for subpoenas would end many white-collar criminal investigations before they had begun.”22 The nature of those investigations usually necessitates reviewing docu- ments before establishing probable cause, and courts have long applied legal doctrines with an eye towards the balance between crime and law enforcement.23 In Fourth Amendment case law, courts have usually relied on categorical approaches to technology, and have largely been resistant to the mosaic theory, which would bring more case-by-case analysis of the volume and importance of the information collected.24 A mo- saic theory applied to financial records would more accurately protect the privacy interests of individuals, which are espe- cially at risk when large volumes of data are collected. But this approach is criticized for lacking clear guidance; how would law enforcement know when they need to request a warrant, and how would judges weigh duration, content, plat- form, and other considerations to make consistent decisions?25 Congressional rulemaking could take into account the 20 See Orin S. Kerr, An Equilibrium-Adjustment Theory of the Fourth Amendment, 125 HARV. L. REV. 476 (2011). Kerr’s article mainly describes his equilibrium theory of the Fourth Amendment, but he explains the lack of protections for financial records by noting the increase in white-collar crime and the difficulty of enforcement. 21 This student Note parallels some of 2023’s public debate over Section 702 of the Foreign Intelligence Surveillance Act (FISA). If limiting collection is not in our national interest, we can partially assuage privacy concerns by regulating access to the collected data. 22 William J. Stuntz, O.J. Simpson, Bill Clinton, and the Transsubstan- tive Fourth Amendment, 114 HARV. L. REV. 842, 860 (2001). 23 Id.; Kerr, supra note 20, at 509. 24 Paul Rosenzweig, In Defense of the Mosaic Theory, LAWFARE (Nov. 29, 2017), https://www.lawfareblog.com/defense-mosaic-theory [https://perma.cc/3SLM-KNKF]. 25 Id. No. 2] MILLER IN A CASHLESS SOCIETY 1021 legitimate law enforcement interests at play,26 while slowing the current one-way ratcheting up of financial surveillance. This Note argues that the financial surveillance of Ameri- cans has gone too far, justifications for it under constitutional principles have made a mess of legal doctrines, and Congress should turn the dial back to a happier medium. Part II ex- plains the history of financial surveillance, starting with the Bank Secrecy Act, continuing with the War on Terror and the Patriot Act, and arriving at our current, near-total financial surveillance structure. It also explains the parallel develop- ments in Fourth Amendment case law. Part III describes how Carpenter’s emphasis on “detailed, encyclopedic, and effort- lessly compiled”27 records that are made pursuant to technol- ogies “indispensable to participation in modern society”28 have made Miller “an unprincipled and unworkable doc- trine,”29 especially in light of changes in financial information since 1976. It describes justifications for the status quo, in- cluding its value to law enforcement, and concludes that no judicial solution adequately balances Americans’ Fourth Amendment rights, basic financial privacy, and legitimate law enforcement interests in complex white-collar investigations. Finally, Part IV suggests some ways that Congress can better protect Americans’ financial privacy, namely by limiting sub- poenas’ duration and adding suppression as a remedy for vio- lations of The Right to Financial Privacy Act. II. A. Bank Secrecy Act and Financial Surveillance The Bank Secrecy Act of 1970 (BSA) and the additional laws that followed were inspired in part by the idea that crim- inals conduct business in cash, and the banks should assist 26 Aziz Z. Huq, How the Fourth Amendment and the Separation of Pow- ers Rise (and Fall) Together, 83 U. CHI. L. REV. 139, 149 (2016). 27 Carpenter v. United States, 138 S. Ct. 2206, 2216 (2018). 28 Id. at 2220. 29 Id. at 2230 (Kennedy, J., dissenting). 1022 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 the government in surveilling those activities.30 As such, the BSA mandated recordkeeping and reporting by banks in order to maintain information that had a “high degree of usefulness in criminal, tax, or regulatory investigations or proceed- ings.”31 In passing that legislation, Congress was concerned about Americans’ use of foreign financial institutions to evade legal or tax obligations.32 Additionally, increases in sophisti- cated criminal activity flowing through domestic financial in- stitutions necessitated increased government visibility of those schemes.33 Law enforcement wanted a way to preserve the records of such crimes, which may have happened years ago and whose only witness was often the bank used to trans- fer funds. As a result, financial institutions were required to make and retain records of transaction details.34 Access to those records by government authorities was to be controlled by the “existing legal process,” which did not limit requests in time or scope.35 Other BSA provisions effectively invert the traditional warrant requirement—instead of the government requesting permission to search one’s papers, businesses are compelled by statute to affirmatively report information to the govern- ment. The BSA first included a provision for banks and other financial institutions to tell the government, through a Cur- rency Transaction Report (CTR), any time someone attempts a cash transaction over $10,000.36 Breaking up the transac- tion into smaller amounts will not get around this reporting 30 Bank Secrecy Act of 1970, Pub. L. No. 91-508, 84 Stat. 1114; Robert J. Olejar, Anti-Money Laundering v. the Right to Privacy, 2008 N.J. LAW. 56, 59. 31 Cal. Bankers Ass’n v. Shultz, 416 U.S. 21, 26 (1974). For an extended discussion on the background and purpose of the BSA, see id. 32 Id. at 27–29. 33 Id. at 27. 34 31 C.F.R. §§ 1010.300, 1010.400 (2022). 35 Cal. Bankers Ass’n, 416 U.S. at 52. The existing legal process is con- trolled by statute since the Supreme Court later declared in Miller that there is no constitutional floor in searches of financial records. United States v. Miller, 425 U.S. 435 (1976). For federal authorities, The Right to Financial Privacy Act controls. 12 U.S.C. §§ 3401–3423. 36 31 C.F.R. § 1010.311 (2022). No. 2] MILLER IN A CASHLESS SOCIETY 1023 requirement,37 and is actually a federal crime itself.38 A $10,000 transaction may seem like a high threshold for an in- dividual, since most people would only exceed it for large pur- chases like a car, a down payment for a house, or Columbia Law tuition. But if the reporting requirement was adjusted for inflation, the 2022 threshold would be approximately $75,000.39 As a result of the unchanged transaction threshold, a high volume of CTRs have been filed in recent years, includ- ing over 16 million in 2019.40 Policymakers saw financial surveillance as a great tool, and over time it was applied to solve problems besides tax eva- sion.41 During the War on Drugs, these tactics were repur- posed to combat cartels, which had been using the banking system to wash their enormous cash profits.42 SARs, which became required after the Annunzio-Wylie Anti-Money Laun- dering Act of 1992, began to alert law enforcement to specific persons or entities relevant to their efforts.43 As noted in the Introduction, these regulations mandate that banks, and now many other organizations, report suspicious or unexplainable financial activity to the government. Institutions are incentiv- ized to over-file SARs defensively because scrutiny from 37 31 C.F.R. § 1010.330(b) (2022). 38 31 U.S.C. § 5324. 39 INFLATION CALCULATOR, FED. RSRV. BANK OF MINNEAPOLIS, https://www.minneapolisfed.org/about-us/monetary-policy/inflation-calcu- lator [https://perma.cc/DP5V-WVQ9] (enter “10000” and “1970”; then press “Calculate”). 40 85 Fed. Reg. 29022, 29023 (May 14, 2020) (to be codified at 31 C.F.R. §§ 1010.310–314, 1021.311–313). For historic data, see also Suspicious Ac- tivity Reports and Cash Transaction Reports, 2000-2015 (table), in Norbert Michel & David Burton, Financial Privacy in a Free Society, THE HERITAGE FOUNDATION (Sept. 23, 2016), https://www.heritage.org/markets-and-fi- nance/report/financial-privacy-free-society [https://perma.cc/KV6V- RRUW]. 41 BSA Timeline 1970-Present, FINCEN, https://www.fincen.gov/re- sources/statutes-and-regulations/bank-secrecy-act/bsa-timeline [https://perma.cc/J4BE-GJNV] (last visited Sept. 10, 2023). 42 Id. 43 Id.; 31 U.S.C. § 5318(g). 1024 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 regulators is most acute when instances of criminal activity are missed.44 When the War on Terror began, policymakers once again turned to financial surveillance as a powerful digital means to defeat real-world, violent crimes. The Patriot Act, in addition to its more infamous provisions on phone tapping and indefi- nite detention, included sections to expand financial reporting and surveillance tools.45 More entities were required to file SARs and CTRs,46 and the Department of the Treasury (Treasury) could now require that all financial institutions search their records for matches on particular names.47 There is no judicial check on this Section 314 process, and it allows law enforcement to start with a target rather than beginning an investigation after receiving a SAR or CTR. Despite its post-9/11 origins, the majority of Treasury requests through this process have been unrelated to terrorism.48 44 Richard Vanderford, ‘Defensive’ SARs Filings Remain an Issue, NY Regulator Says, MLEX (Apr. 15, 2021), https://mlexmarketin- sight.com/news/insight/defensive-sars-filings-remain-an-issue-ny-regula- tor-says [https://perma.cc/L5XK-L9ZP]; Carl Brown, Not Enough Needles and Too Much Hay: The Problem with Suspicious Activity Reports, GRC WORLD FS. (Feb. 2, 2021), https://www.grcworldforums.com/financial- crime/not-enough-needles-and-too-much-hay-the-problem-with-suspicious- activity-reports/719.article [https://perma.cc/4TXP-HNWF]; V. Gerard Comizio, Kevin L. Petrasic, Lawrence D. Kaplan & Helen Y. Lee., FINCEN SHARPENS TEETH WITH NEW ENFORCEMENT DIVISION – PRACTICAL CONSIDER- ATIONS FOR AVOIDING FINCEN’S BITE, PAUL HASTINGS, 3 (2013), https://web- storage.paulhastings.com/Documents/PDFs/stay_current_fincen_sharp- ens_teeth.pdf [https://perma.cc/EDS2-EB5L]. 45 Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism (USA PATRIOT) Act of 2001, Pub. L. No. 107-56, 115 Stat. 272 (2001). 46 Id. §§ 356, 365; 31 C.F.R. § 1010.520 (2022). 47 USA PATRIOT Act § 314; see also FINCEN, FinCEN’s 314(a) Fact Sheet (Aug. 22, 2023), https://www.fincen.gov/sites/de- fault/files/shared/314afactsheet.pdf [https://perma.cc/8EH8-W38Q] (facili- tating the standard subpoena process so investigators are then aware of which banks to request further information from). 48 FINCEN, FinCEN’s 314(a) Fact Sheet (Aug. 22, 2023), https://www.fincen.gov/sites/default/files/shared/314afactsheet.pdf [https://perma.cc/8EH8-W38Q]. No. 2] MILLER IN A CASHLESS SOCIETY 1025 In the past year, Congress has also attempted to expand reporting requirements beyond financial services.49 Already, the term “financial institution” had been expanded to include travel agencies, casinos, car and boat dealerships, the Postal Service, sellers of jewelry or precious metals, and any other business that Treasury thinks would have a “high degree of usefulness in criminal, tax, or regulatory matters.”50 Organi- zations may each have different thresholds for reporting re- quirements; for example, Money Service Businesses must re- port suspicious activity over $2,000 while the threshold for casinos is $5,000.51 All financial institutions must verify and record the identity of transmitters, and banks must also cre- ate baselines for normal customer behavior and then monitor for anomalous transactions.52 49 Peter D. Hardy & James Mangiaracina, Closing the Gate: House Adopts ENABLERS Act Amendment to 2023 NDAA, CONSUMER FIN. MONI- TOR (July 21, 2022), https://www.consumerfinancemoni- tor.com/2022/07/21/closing-the-gate-house-adopts-enablers-act-amend- ment-to-2023-ndaa/ [https://perma.cc/K48N-Q4CB]. The ENABLERS Act, if passed as part of the 2023 National Defense Authorization Act, would have added corporate formation and trust services, payment processors, and cer- tain legal and accounting services to the entities covered by the Bank Se- crecy Act’s recordkeeping and reporting requirements. A previous version had also included art and antiquities dealers. The stated purpose of this legislation is to give authorities a broader net of potentially illicit transac- tions to watch over, and while it was ultimately removed from the 2023 NDAA, its supporters, including President Biden, hope to revive it in the future. Will Fitzgibbon, US Senate Blocks Major Anti-Money Laundering Bill, the Enablers Act, INT’L CONSORTIUM OF INVESTIGATIVE JOURNALISTS (Dec. 12, 2022), https://www.icij.org/investigations/pandora-papers/us-sen- ate-blocks-major-anti-money-laundering-bill-the-enablers-act/ [https://perma.cc/95CW-J4S3]. 50 31 U.S.C. § 5312(a)(2). 51 FINCEN, SUSPICIOUS ACTIVITY REPORTING GUIDANCE FOR CASINOS 3 (2003), https://www.fincen.gov/sites/default/files/shared/sar_guidance_ca- sino.pdf [https://perma.cc/8T96-DQL2]; Money Services Business (MSB) Suspicious Activity Reporting, FINCEN, https://www.fincen.gov/money-ser- vices-business-msb-suspicious-activity-reporting [https://perma.cc/4J6A- RYUR]. 52 31 C.F.R. § 1010.312 (2021); 31 C.F.R. § 1010.410 (2016); 31 C.F.R. § 1010.220 (2022); see, e.g., 31 C.F.R. § 1020.210 (2022) (describing the pro- gram requirements for banks); 31 C.F.R. § 1020.315(h). 1026 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 Information from the financial surveillance system does not stay with Treasury. Law enforcement across the nation has access to an online database established by the Financial Crimes Enforcement Network (FinCEN),53 where queries of individual names can return SARs or other financial data on the targets.54 The Anti-Money Laundering Act of 2020 ena- bled further coordination and information sharing between FinCEN and law enforcement across the country.55 There cer- tainly will be a lot of information to share—in fiscal year 2019, more than 20 million total BSA reports were filed by over 97,000 American financial institutions.56 53 What We Do, FINCEN, https://www.fincen.gov/what-we-do [https://perma.cc/ARU8-YDML] (last visited Sept. 10, 2023) (“FinCEN’s mission is to safeguard the financial system from illicit use and combat money laundering and promote national security through the collection, analysis, and dissemination of financial intelligence and strategic use of fi- nancial authorities.”). 54 FINCEN, FACT SHEET: THE FINCEN PORTAL, https://www.fin- cen.gov/sites/default/files/shared/Facts_FinCENPortal.pdf [https://perma.cc/C45T-WF5A] (last visited Sept. 10, 2023); FINCEN, FACT SHEET: FINCEN QUERY, https://www.fincen.gov/sites/de- fault/files/shared/Facts_FinCENQuery.pdf [https://perma.cc/7E9Q-7WSY] (last visited Sept. 10, 2023). 55 Norbert Michel & Jennifer Schulp, Revising the Bank Secrecy Act to Protect Privacy and Deter Criminals, CATO INST. (July 26, 2022), at 8, https://www.cato.org/sites/cato.org/files/2023-04/policy-analysis-932-up- date-4-12-23.pdf [https://perma.cc/4BCW-SL22]. 56 What is the BSA Data?, FINCEN, https://www.fincen.gov/what-bsa- data [https://perma.cc/VUZ8-BE5G] (last visited Sept. 10, 2023). The secu- rity of this enormous volume of data may also be questionable, as the federal government does not have a spotless record on information security, with notable hacking and leaking incidents. See David E. Sanger & Julie Hirsch- feld Davis, Hacking Linked to China Exposes Millions of U.S. Workers, N.Y. TIMES (June 4, 2015), https://www.nytimes.com/2015/06/05/us/breach-in-a- federal-computer-system-exposes-personnel-data.html [https://perma.cc/BD4K-P2D2]; FinCEN Files: All You Need to Know About the Documents Leak, BBC NEWS (Sept. 21, 2020), https://www.bbc.com/news/uk-54226107 [https://perma.cc/RR8A-4P4X]. No. 2] MILLER IN A CASHLESS SOCIETY 1027 B. The Fourth Amendment’s Evolution and Exclusion of Financial Records The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, sup- ported by Oath or affirmation, and particularly de- scribing the place to be searched, and the persons or things to be seized.57 The Fourth Amendment was largely a response to British use of “writs of assistance, a form of general warrant” that did not specify the person or place to be searched and did not re- quire evidence to be presented to a judge.58 In the early repub- lic, state constitutional analogues were used to protect against arbitrary searches of one’s home without specific, judicially- approved warrants.59 Scholars largely agree that Fourth Amendment doctrine is now somewhat unclear, although they disagree on why that is.60 Scholars, and courts too, have struggled with what values the Fourth Amendment prioritizes and how those should be balanced against the needs of law enforcement and public safety.61 Most of Fourth Amendment law now focuses on de- termining whether something is a search or not, rather than the reasonableness question, because searches have been deemed presumptively unreasonable without a warrant,62 57 U.S. CONST. amend. IV. 58 Laura K. Donohue, The Original Fourth Amendment, 83 U. CHI. L. REV. 1181, 1194 (2016). 59 Id. at 1276–80. Since federal criminal investigations were rare at the time, and the Fourth Amendment did not apply to the states yet, there was not much case law directly applying the Amendment. 60 See Orin S. Kerr, Four Models of Fourth Amendment Protection, 60 STAN. L. REV. 503, 505 (2007) (compiling various opinions on the cause of confusion in Fourth Amendment doctrine). 61 Anna Lvovsky, Fourth Amendment Moralism, 166 U. PA. L. REV. 1189, 1204–05 (2018). 62 See infra note 69 and accompanying text. This approach is not with- out criticism. See Carpenter v. United States, 138 S. Ct. 2206, 2238, 2243– 45 (2018) (Thomas, J., dissenting). 1028 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 and even subpoenas are not sufficient for records that meet the search test.63 Traditionally, categorizing an action as a “search” hinged on whether an interest in a “tangible property” right had been invaded.64 This property-based understanding of the Fourth Amendment was mostly static until the mid-20th century. It allowed consistency and predictability for law enforcement, courts, lawyers, and the public, but came to be under-exclu- sive.65 With technological changes, new investigative tactics became possible which were intrusive, but not quite tres- passes. In 1967, the Supreme Court was presented squarely with the question of whether there could be a search when there was not a physical intrusion.66 The Supreme Court shifted the doctrine significantly in Katz v. United States, taking into account expectations of pri- vacy.67 There, police had used a recording device to capture a suspect’s phone call from a public telephone.68 The Court made clear that a physical trespass was no longer a require- ment of search, and that searches without warrants were pre- sumptively unreasonable.69 Although the officers may have objectively had probable cause for their actions, the majority held that the lack of review by a judicial officer was decisive.70 But Katz is most famous for the rule that came from a concur- rence. Justice Harlan pronounced that in determining if a search had occurred, a court should consider whether the de- fendant had manifested a subjective expectation of privacy 63 Carpenter v. United States, 138 S. Ct. 2206, 2221 (2018). Indeed, one of the main arguments of Justice Kennedy’s dissent was that the subpoena process provided sufficient procedural checks. Id. at 2228 (Kennedy, J., dis- senting). The majority, of course, disagreed, stating “this Court has never held that the Government may subpoena third parties for records in which the suspect has a reasonable expectation of privacy.” Id. at 2221. 64 Katz v. United States, 389 U.S. 347, 352–53 (1967). 65 Id. at 353. 66 Id. at 350. 67 Id. at 351 (“[W]hat he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.”). 68 Id. at 348. 69 Id. at 352–53, 357. 70 Id. at 356. No. 2] MILLER IN A CASHLESS SOCIETY 1029 and whether society was prepared to accept that expectation as reasonable.71 After Katz, lower courts applied the expectation of privacy test to financial records. The Fifth Circuit reasoned in United States v. Miller that since the government could not compel someone to produce their “private papers to establish a crimi- nal charge against him,” forcing a third party to do so would also violate a target’s rights.72 After finding distillery equip- ment in a truck and warehouse rented by Miller, the United States Attorney’s Office subpoenaed his banks for his finan- cial records.73 Miller was not notified at the time and later argued that the prosecution should not have been able to use those records to prove his alcohol production and tax evasion charges.74 The issue was whether the subpoena, which was not issued by a court or grand jury, qualified as adequate legal process under the BSA and the Fourth Amendment.75 While the BSA allowed government access to financial records through the existing legal process, the Fifth Circuit ruled sub- poenas were insufficient as a constitutional matter.76 However, the Supreme Court reversed that decision, and in the process announced the beginnings of an explicit third- party doctrine.77 The Court stated that there was no reasona- ble expectation of privacy in financial records or other infor- mation voluntarily turned over to third parties, and the BSA’s retention provisions did not change that.78 Since there was no 71 Id. at 361 (Harlan, J., concurring). 72 United States v. Miller, 500 F.2d 751, 757 (5th Cir. 1974) (quoting Boyd v. United States, 116 U.S. 616, 622 (1886)), rev’d, 425 U.S. 435 (1976). 73 United States v. Miller, 425 U.S. 435, 437 (1976). 74 Id. at 438. 75 Miller, 500 F.2d at 757–58. 76 Id. 77 Miller, 425 U.S. at 444. The third-party doctrine holds, generally, that people have no reasonable expectation of privacy in information handed over to third parties. Therefore, it is not a search when the govern- ment accesses this data. Some scholars argue that this was always an im- plicit part of Fourth Amendment law, with the labeling just changing in the 1970s. See Orin S. Kerr, Katz Has Only One Step: The Irrelevance of Sub- jective Expectations, 82 U. CHI. L. REV. 113, 115 (2015). 78 Miller, 425 U.S. at 441–43. 1030 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 protectable Fourth Amendment interest in financial records, even a defective subpoena did not raise constitutional con- cerns.79 The majority distinguished Katz by explaining that “the nature of the particular documents” was key in determin- ing whether they were knowingly exposed to the public or meant to be kept as private, and decided that checks and de- posit slips were better categorized as negotiable instruments “exposed to [bank] employees in the ordinary course of busi- ness,” rather than as the defendant’s personal papers.80 It was therefore not a search when the prosecutor used a subpoena instead of a warrant to access this information, “even if a crim- inal prosecution is contemplated at the time of the subpoena is issued.”81 Since no “search” occurred, there were no Fourth Amendment issues. The third-party doctrine effectively ended any hope that financial records would be protected by the Fourth Amend- ment, but Congress responded to the decision by enacting The Right to Financial Privacy Act.82 The law restricts federal au- thorities to accessing an individual’s financial records by cus- tomer authorization, administrative subpoena, search war- rant, judicial subpoena, or written request.83 Importantly, it contains a notification requirement when the federal govern- ment requests a customer’s information, but there are excep- tions, including whenever secrecy is believed to be necessary for an ongoing investigation.84 The RFPA also gave individu- als standing to challenge a subpoena under the Act,85 but they need to prove that the “records requested are not relevant to 79 Id. at 441 n.2. 80 Id. at 442. 81 Id. at 444. 82 Right to Financial Privacy Act of 1978, 12 U.S.C. §§ 3401–3423. Con- gress stated the RFPA was a response to Miller, but Miller simply upheld the BSA statutory scheme which Congress itself created and has since ex- panded. The RFPA does not apply to state and local authorities, but some states have similar statutes. Right to Financial Privacy Act, ELECTRONIC PRIVACY INFORMATION CENTER, https://epic.org/the-right-to-financial-pri- vacy-act/ [https://perma.cc/8YPY-B3S4] (last visited Sept. 8, 2023). 83 12 U.S.C. §§ 3404–08. 84 12 U.S.C. §§ 3404–09. 85 12 U.S.C. § 3410. No. 2] MILLER IN A CASHLESS SOCIETY 1031 the agency’s” legitimate law enforcement inquiry, which can be defeated if the government shows it “touches a matter un- der investigation.”86 The Court’s other cases since 1976 have recognized that Fourth Amendment law must evolve with changes in technol- ogy. In Kyllo v. United States, the majority was concerned with preserving the “degree of privacy against government that existed when the Fourth Amendment was adopted.”87 There, a thermal imaging tool was used from a public street to determine that certain areas of a house were abnormally warm, leading to further investigation for marijuana produc- tion.88 The Court was confronted with whether new technol- ogy could change the extent of privacy enjoyed by Americans, as naked-eye surveillance of the home would not have been a search.89 In declaring that this was indeed a search, it noted “the rule we adopt must take account of more sophisticated systems that are already in use or in development.”90 While focus had shifted away from a property-based con- ception of the Fourth Amendment, the Supreme Court re- minded lower courts in U.S. v. Jones that the Katz expecta- tions test was not the only part of the search analysis.91 Katz was an addition to the common law trespass test, and an 86 Sandsend Fin. Consultants, Ltd. v. Fed. Home Loan Bank Bd., 878 F.2d 875, 882 (5th Cir. 1989). There are also procedural grounds on which a plaintiff could succeed, if “the agency has not substantially complied with the RFPA.” Id. 87 Kyllo v. United States, 533 U.S. 27, 34 (2001). 88 Id. at 29–30. 89 Id. at 31–32. For example, if there was snow on the roof that was melting abnormally fast, a police officer would not need a search warrant to observe this. Here, the technology only captured heat emitted from the home, not heat inside the home. While these are often very similar, the dis- tinction is critical, although fuzzy. The technology enhanced the view of the outside of the home but did not technically peer inside of it. An advanced listening device could operate the same way, capturing conversations that occur inside the home but only by picking up external sounds which are too faint for an unassisted ear to hear. See id. at 35. 90 Id. at 36. 91 United States v. Jones, 565 U.S. 400, 406–07 (2012). 1032 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 action could be ruled a search under either framework.92 In Jones, placing a tracker on someone’s car was ruled a search because the act itself was a trespass, even though the defend- ant did not have an expectation of privacy on public roads.93 In 2018, Carpenter upset the third-party doctrine when the Court declared that cell site location information (CSLI) was protectable even though it was voluntarily given to private companies.94 There, the majority distinguished information given to third parties through activities “indispensable to par- ticipation in modern society.”95 Since there was no way to stop sharing the data while using a phone, “in no meaningful sense does the user voluntarily” consent to sharing.96 The Court also took issue with the amount of data being shared, and “the na- ture of the particular documents sought” there was pivotal too, as location data is extensive, can accurately track where a phone travels for years, and may reveal particularly private information.97 However, the Carpenter majority explicitly said Miller was not being overturned, as they considered checks and deposit slips less intrusive than cell site location data.98 C. Miller after Carpenter Unsurprisingly, financial records search cases since Car- penter have pointed to its clear validation of Miller.99 Courts have also extended Miller to new forms of financial technol- ogy. In Zietzke v. United States, the district court realized it was in the “unenviable position” of attempting to understand how Carpenter distinguished bank records from CSLI, since “little 92 Id. at 409. 93 Id. at 404–05. 94 Carpenter v. United States, 138 S. Ct. 2206, 2220 (2018). 95 Id. 96 Id. 97 Id. at 2219–20. However, the location data at issue here was only created when the defendant “made or received calls.” Id. at 2214. 98 Id. at 2220. 99 Presley v. United States, 895 F.3d 1284, 1291 (11th Cir. 2018); Standing Akimbo, LLC v. United States through Internal Revenue Serv., 955 F.3d 1146, 1165 (10th Cir. 2020). No. 2] MILLER IN A CASHLESS SOCIETY 1033 guidance” had been given for the task.100 There, when faced with a summons for a user’s records from a cryptocurrency ex- change, the court focused on Carpenter’s discussion of physical location.101 It noted that there was no location surveillance in these cryptocurrency transactions, so the movant could not point to the same concerns at issue in Carpenter.102 Accord- ingly, the petitioner’s challenge to the records request was de- nied.103 Only one circuit court appears to have waded into this is- sue so far. In United States v. Gratkowski, the Fifth Circuit confronted whether an individual had a right to privacy in his information on the Bitcoin blockchain. The court concluded that the defendant’s records were more similar to the bank records in Miller than the location data in Carpenter.104 The court reasoned that using Bitcoin is not an inescapable part of daily life and that “it is well known that each Bitcoin transac- tion is recorded in a publicly available blockchain.”105 In re- gard to the transaction data that was subpoenaed directly from Coinbase, the court thought “a person’s virtual currency transactions” are infrequent and do not provide an “intimate window” into their life, and like in Miller, the information was voluntarily provided to a third party.106 They also relied on the fact that limited information—the amount, the sending party, and the receiving party—was gathered from his trans- actions.107 While the D.C. Circuit sidestepped this question in Wit- aschek v. District of Columbia, it left open that Carpenter 100 Zietzke v. United States, 426 F. Supp. 3d 758, 768 (W.D. Wash. 2019). 101 Id. 102 Id. at 769. 103 Id. 104 United States v. Gratkowski, 964 F.3d 307, 312 (5th Cir. 2020). 105 Id. Thus, the implication is that there is no expectation of privacy. 106 Id. See also United States v. Miller, 425 U.S. 435, 441–43 (1976). 107 Gratkowski, 964 F.3d at 311–12. In this case, the limited infor- mation of sender and receiver was sufficient as evidence, since the defend- ant had paid for access to a child exploitation website. 1034 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 might impact the privacy analysis for financial records.108 There, tax enforcement investigators had used summonses to confirm that the defendant was lying about his part-year res- idency in the District.109 Defendant argued that the infor- mation was protectable after Carpenter because it revealed his location history, and that it should be suppressed since the request had not been presented to a neutral magistrate.110 But since the conduct at issue took place before Carpenter, the court avoided the issue and stated that the good-faith excep- tion would apply even if the documents implicated a legiti- mate privacy interest.111 Meanwhile, state courts have histor- ically produced mixed results on the reasonable expectation of privacy in financial records, and the one that has taken it up post-Carpenter pointed to the upholding of Miller.112 In this way, the third-party doctrine can be straightfor- ward for lower courts to apply; they can use the categorical tests and wait until the Supreme Court adds any new forms of technology to the exceptions list. However, in isolated in- stances, courts have been accepting of a mosaic theory of the Fourth Amendment to grapple with the potential for data ag- gregation, though not applied directly to financial records.113 The majority in Carpenter also sidestepped the question of whether accessing fewer days of CSLI would have produced the same result, lending support to the idea that the volume 108 Witaschek v. District of Columbia, 254 A.3d 1151, 1157 (D.C. Cir. 2021). 109 Id. at 1154. 110 Id. at 1157. 111 Id. at 1157–58. 112 State v. Adame, 476 P.3d 872, 876–77 (N.M. 2020). 113 See infra Section III.C.2; Commonwealth v. Henley, 171 N.E.3d 1085, 1102–07 (Mass. 2021) (rejecting the application of the third-party doc- trine to public transportation and agreeing that an extensive search of one’s metro card records could constitute a search under the mosaic theory, while holding that two days’ worth of data was not a search); Kelly v. United States, 281 A.3d 610, 614 (D.C. Cir. 2022) (determining that the two-day real-time tracking of a suspect’s metro card usage was not a search by anal- ogizing to Henley and Carpenter, and weighing the amount of data received rather than applying a simple categorical approach to metro cards). No. 2] MILLER IN A CASHLESS SOCIETY 1035 of data, and not just categorical approaches to technology, may impact whether something is a search.114 III. A. Changes in Financial Technology and Consumer Practices With a cashless trail, you were fated always to be what you had always been; you couldn’t flee far from your name, your purchases, even your network of friends. You were always, by your cards or cell phone, outed as yourself.115 1. Technology and Consumer Practices As law enforcement’s tools have expanded, changes in tech- nology and Americans’ habits have contributed to making fi- nancial records a one-stop investigative shop. Over time, the information within financial records has greatly expanded.116 No longer do people use credit cards oc- casionally, checks often, and cash as the primary means for transactions. Now, using cash has become increasingly rare as finance has been digitalized on the consumers’ side as well; cards and mobile pay dominate retail transactions.117 Finan- cial “[t]echnology is no longer a quirky addition to our daily routines,” it is essential to operating in the modern world.118 114 “[W]e need not decide whether there is a limited period for which the Government may obtain an individual’s historical CSLI free from Fourth Amendment scrutiny, and if so, how long that period might be. It is sufficient for our purposes today to hold that accessing seven days of CSLI constitutes a Fourth Amendment search.” Carpenter v. United States, 138 S. Ct. 2206, 2217 n.3 (2018). 115 Nathan Heller, Imagining a Cashless World, NEW YORKER (Oct. 3, 2016), https://www.newyorker.com/magazine/2016/10/10/imagining-a-cash- less-world [https://perma.cc/WS5S-T9YB]. 116 Gentithes, supra note 13, at 1075–76. 117 See generally CUBIDES & O’BRIEN, supra note 16. 118 Nicholas Anthony, Why Don’t Americans Have Stronger Financial Privacy Rights?, CATO INST. (Oct. 28, 2021), https://www.cato.org/blog/why- 1036 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 The pandemic accelerated existing trends in the digitaliza- tion of finance.119 From 2016 to 2021, cash usage share, by percentage of all payments, decreased by 11%.120 By 2022, over 40% of Americans said “none of their purchases in a typ- ical week are paid for using cash, up from 29% in 2018 and 24% in 2015.”121 Americans used less cash because of chang- ing preferences towards credit cards and increases in peer-to- peer mobile app payments, among other reasons.122 Card use is often quicker and users receive rewards from payment pro- cessors for each swipe. Additionally, cash usage decreased because consumers are making fewer purchases in person, instead substituting online retail purchases and remote payments for food and drinks.123 Online purchases made from the home, with possi- bly more expectations of privacy, show up on one’s bank state- ment just the same as a trip to the mall. Most Americans buy things online using smartphones or computers, and nearly a third make weekly purchases online.124 These statistics are more pronounced in younger Americans, with over 90% of those between the ages 18 to 49 using smartphones to make online purchases.125 Additionally, by 2022, over 75% of dont-americans-have-stronger-financial-privacy-rights [https://perma.cc/P2EP-T2GU]. 119 Kate Marino, The Pandemic-Fueled Decline of Cash, AXIOS (July 16, 2021), https://www.axios.com/2021/07/16/legal-cash-economy-decline-pan- demic [https://perma.cc/8ZWC-PPSU]. 120 CUBIDES & O’BRIEN, supra note 16, at 6. 121 Michelle Faverio, More Americans Are Joining the ‘Cashless’ Econ- omy, PEW RSCH. CTR. (Oct. 5, 2022), https://www.pewresearch.org/fact- tank/2022/10/05/more-americans-are-joining-the-cashless-economy/ [https://perma.cc/74EH-3CZH]. 122 CUBIDES & O’BRIEN, supra note 16, at 9–11. 123 Id. at 6–8. Between 2016 and 2021, the share of in-person purchases and peer-to-peer payments dropped from 92% to 82%. 124 Michelle Faverio & Monica Anderson, For Shopping, Phones Are Common and Influencers Have Become a Factor—Especially for Young Adults, PEW RSCH. CTR. (Nov. 21, 2022), https://www.pewresearch.org/fact- tank/2022/11/21/for-shopping-phones-are-common-and-influencers-have- become-a-factor-especially-for-young-adults/ [https://perma.cc/3ZTU- TT6D]. 125 Id. No. 2] MILLER IN A CASHLESS SOCIETY 1037 Americans had already used one of PayPal, Zelle, Venmo, or Cash App for peer-to-peer payments, citing their ease of use.126 Government authorities have easy access to all of those transactions, even if some are initiated in private spaces. A cashless society increases not only the volume of finan- cial data available but also alters its character. When the en- tries that appear in financial statements are comprehensive, they reveal intimate information that raises further privacy concerns.127 Each credit card purchase pinpoints the exact lo- cation and time that you were at a store or subway stop. Fi- nancial information can be particularly sensitive in the First Amendment context.128 Our bank records can show which po- litical party someone donated to, which church they attend, and any legal but disfavored organizations or activities they participate in.129 There are also network effects at play.130 The details gleaned from financial records increase exponen- tially as a comprehensive picture of a person’s life is drawn, and artificial intelligence may be used to “find patterns and relations that humans would never consider.”131 126 Monica Anderson, Payment Apps Like Venmo and Cash App Bring Convenience—and Security Concerns—to Some Users, PEW RSCH. CTR. (Sept. 8, 2022), https://www.pewresearch.org/fact-tank/2022/09/08/pay- ment-apps-like-venmo-and-cash-app-bring-convenience—and-security-con- cerns—to-some-users/ [https://perma.cc/4BH6-KZJ3]. 127 Peter P. Swire, Financial Privacy and the Theory of High-Tech Gov- ernment Surveillance, 77 WASH. U. L.Q. 461, 469 (1999). 128 Gentithes, supra note 13, at 1074 (citing Buckley v. Valeo, 424 U.S. 1 (1976)). 129 The privacy worry is not mainly that these legal activities will be prosecuted, but that “[f]reedom of thought, expression, and action are key to unlocking each person’s unique potential to contribute to society. Untar- geted government surveillance programs, even well-intentioned ones, threaten that freedom.” Commissioner Hester Peirce, Statement of Hester M. Peirce in Response to Release No. 34-88890, SEC (May 15, 2020), https://www.sec.gov/news/public-statement/peirce-statement-response-re- lease-34-88890-051520 [https://perma.cc/XP5N-Q2FA] (related to surveil- lance in securities markets). 130 Swire, supra note 127, at 469. 131 William Magnuson, Artificial Financial Intelligence, 10 HARV. BUS. L. REV. 337, 358 (2020). 1038 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 What exactly are privacy advocates worried about when discussing the financial surveillance infrastructure? To many, granting the government more power to surveil transactions, and making it easier to block people from their finances,132 would be extremely dangerous.133 They often point to the po- tential for authoritarian actions and note how “[m]any busi- nesses, dissidents, and human rights groups maintain ac- counts outside the countries where they are active” in order to 132 Bradford Newman, The Digital U.S. Dollar Is a Threat to Civil Lib- erties, BITCOIN MAG. (July 20, 2022), https://bitcoinmagazine.com/cul- ture/digital-dollar-threat-civil-liberties [https://perma.cc/DQM3-Q96M] (“Last year the Canadian government ordered financial firms to cease facil- itating any transactions from 34 crypto wallets tied to funding trucker-led protests over COVID-19 vaccine mandates.”). See also Walter Olson, Can- ada Says It’s Un-Freezing Protestors’ Accounts. The Controversy Isn’t Going Away., CATO INST. (Feb. 25, 2022), https://www.cato.org/blog/canada-says- its-un-freezing-demonstrators-bank-accounts-controversy-isnt-going-away [https://perma.cc/8T4Q-3CSE]. While the Canadian government did not need a central bank digital currency to take these actions, privacy advocates see more government control in this space as dangerous because it imposes fewer steps that could be used to curtail the lawless use of such powers. 133 Justin Amash (@justinamash), X (formerly TWITTER) (Aug. 31, 2023, 11:58 AM), https://twitter.com/justinamash/status/1697277614975590851 [https://perma.cc/SWP2-FMN7] (“Decentralize money. No digital dollar. A digital U.S. currency would be one of the most dangerous developments in history. When government can simply flip a switch to block all your trans- actions, it controls your entire life. We need a wall of separation between money and state.”); see also Governor Ron DeSantis Announces Legislation to Protect Floridians from a Federally Controlled Central Bank Digital Cur- rency and Surveillance State, OFF. OF GOVERNOR RON DESANTIS (Mar. 20, 2023), https://www.flgov.com/2023/03/20/governor-ron-desantis-announces- legislation-to-protect-floridians-from-a-federally-controlled-central-bank- digital-currency-and-surveillance-state/ [https://perma.cc/5TQX-M2KY]. While the proposed legislation is of dubious constitutionality, its existence highlights the concern some influential political constituencies have with the creation of a Central Bank Digital Currency (CBDC). See Jesse Hamil- ton, Florida’s DeSantis Waging Toothless Campaign Against Digital Dol- lars, Lawyers Say, COINDESK (May 17, 2023), https://www.coindesk.com/policy/2023/05/17/floridas-desantis-waging- toothless-campaign-against-digital-dollars-lawyers-say/ [https://perma.cc/8APB-J8EL]. No. 2] MILLER IN A CASHLESS SOCIETY 1039 avoid suppression.134 During the Hong Kong protests, pro-de- mocracy protestors waited in long lines at subway stations to purchase their trips with cash, so that financial surveillance couldn’t place them at the protest.135 The existence of surveil- lance, in this field and others, produces chilling effects and cloaking costs for legitimate activities either forgone or partic- ipated in at higher costs.136 The “banking transactions of an individual give a fairly accurate account of his religion, ideol- ogy, opinions, and interests,”137 and many innocent people could have good reasons to keep that information from gov- ernment authorities. The Canadian government’s response to the 2022 “Freedom Convoy” protest makes some worry that “even relatively free governments are sometimes willing to use private financial information to quell nonviolent pro- tests.”138 There, without court orders, authorities froze bank accounts tied to persons associated with a disruptive, anti- government protest.139 New abortion laws mean that the related financial data is now relevant to many state authorities, and is therefore ac- cessible without a warrant.140 While transaction data usually 134 Norbert Michel & David Burton, Financial Privacy in a Free Society, HERITAGE FOUND. (Sept. 23, 2016), https://www.heritage.org/markets-and- finance/report/financial-privacy-free-society [https://perma.cc/5HVA- FCK2]. 135 How to Fix the Internet, Podcast Episode 108: How Private Is Your Bank Account?, ELEC. FRONTIER FOUND., at 08:40 (Jan. 18, 2022), https://www.eff.org/deeplinks/2021/12/who-peering-your-bank-account [https://perma.cc/GWK3-PYKX]. 136 Swire, supra note 127, at 473–75. 137 Cal. Bankers Ass’n v. Shultz, 416 U.S. 21, 85 (1974) (Douglas, J., dissenting). 138 Michel & Schulp, supra note 55, at 14. 139 Walter Olson, Canada: In a Blow to Liberty, Government Invokes Emergencies Act Against Domestic Protests, CATO INST. (Feb. 16, 2022), https://www.cato.org/blog/canada-invokes-emergencies-act-against-domes- tic-protests [https://perma.cc/S4T4-M9KS]. 140 Ron Lieber & Tara Siegel Bernard, Payment Data Could Become Evidence of Abortion, Now Illegal in Some States, N.Y. TIMES (June 29, 2022), https://www.nytimes.com/2022/06/29/business/payment-data-abor- tion-evidence.html [on file with the Columbia Business Law Review]; CHRIS 1040 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 does not show the exact item purchased, the inference may be simpler when payment is to an online medication abortion ser- vice.141 The examination of financial records does not need to prove conclusive either—related purchases or location evi- dence could be used to build probable cause for a more sweep- ing search.142 In the wake of Dobbs v. Jackson Women’s Health Organization,143 many bank executives and healthcare spending account administrators declined to com- ment on whether they would respond to subpoenas for such information.144 Others claimed they would “not comply with requests for medical expense data—including from law en- forcement and other governmental entities—unless we are specifically compelled by law to do so.”145 But the law as cur- rently written and interpreted does indeed compel them to comply with “simple subpoena[s]” from law enforcement.146 While some financial institutions may attempt to fight these subpoenas harder than in the past, “prosecutors may not say exactly what they’re investigating when they ask for transac- tion records,” making real pushback more unlikely.147 In response to concerns about access to bank accounts and credit cards, some major cities such as Philadelphia, San Francisco, and New York City “have passed legislation D. LINEBAUGH, CONG. RSCH. SERV., LSB10786, ABORTION, DATA PRIVACY, AND LAW ENFORCEMENT ACCESS: A LEGAL OVERVIEW 1 (2022). 141 Maggie Koerth & Amelia Thomson-DeVeaux, As States Banned Abortion, Thousands More Americans Got Pills Online Anyway, FIVETHIR- TYEIGHT (Nov. 1, 2022), https://fivethirtyeight.com/features/medication- abortion-after-dobbs/ [https://perma.cc/ZTJ9-8FXY]. See David W. Chen & Pam Belluck, Wyoming Becomes First State to Outlaw the Use of Pills for Abortion, N.Y. TIMES (Mar. 17, 2023), https://www.ny- times.com/2023/03/17/us/wyoming-abortion-pills-ban.html [on file with the Columbia Business Law Review]. 142 The Fourth Amendment has been incorporated against the states. See, e.g., Mapp v. Ohio, 367 U.S. 643, 655 (1961); Ker v. California, 374 U.S. 23, 30–31 (1963). 143 Dobbs v. Jackson Women’s Health Org., 142 S. Ct. 2228 (2022). 144 Lieber & Siegel Bernard, supra note 140. 145 Id. 146 Id. 147 Id. No. 2] MILLER IN A CASHLESS SOCIETY 1041 forbidding most merchants from refusing to accept cash.”148 These laws also protect privacy. However, no such law exists at the national level, and some scholars even argue that more should be done by policymakers to eliminate cash com- pletely.149 While financial exclusion could be alleviated by en- suring all Americans have bank accounts, such as through the looming possibility of a Central Bank Digital Currency or Cen- tral Bank retail accounts,150 privacy advocates are rightly worried about the potential implications of a cashless society. 2. Carpenter’s Growing Inconsistencies From the outset, critics noted that much of Carpenter’s rea- soning is inconsistent with the Court’s precedents. In dissent, Justice Kennedy lamented that the majority had injected con- fusion into the doctrine by rejecting a “straightforward appli- cation of Miller.”151 Instead, the Carpenter majority attempted to leave stand- ing much of the prior case law, while also creating a new class of digital data to which the third-party doctrine would not 148 Pamela Paul, The Cost of Going Cashless, N.Y. TIMES (Nov. 13, 2022), https://www.nytimes.com/2022/11/13/opinion/cashless-pay-prob- lem.html [on file with the Columbia Business Law Review]. 149 James J. McAndrews & Kenneth S. Rogoff, Should We Move to a Mostly Cashless Society?, WALL ST. J. (Sept. 24, 2017), https://www.wsj.com/articles/should-we-move-to-a-mostly-cashless-society- 1506305220 [on file with the Columbia Business Law Review]; Lawrence H. Summers, It’s Time to Kill the $100 Bill, WASH. POST (Feb. 16, 2016), https://www.washingtonpost.com/news/wonk/wp/2016/02/16/its-time-to- kill-the-100-bill/ [https://perma.cc/5KV8-T8MF]. 150 See Donna Fuscaldo, Postal Service Gets into Banking, Again, AARP (Mar. 22, 2022), https://www.aarp.org/money/investing/info-2022/restart- ing-postal-banking-services.html [https://perma.cc/JS25-EYDA]; John Crawford, Lev Menand & Morgan Ricks, FedAccounts: Digital Dollars, 89 GEO. WASH. L. REV. 113, 125–27 (2021); BD. OF GOVERNORS OF THE FED. RSRV. SYS., MONEY AND PAYMENTS: THE U.S. DOLLAR IN THE AGE OF DIGITAL TRANSFORMATION 14-20 (Jan. 2022), https://www.federalreserve.gov/publi- cations/files/money-and-payments-20220120.pdf [https://perma.cc/5CAP- MJ9Z]. 151 Carpenter v. U.S., 138 S. Ct. 2206, 2230 (2018) (Kennedy, J., dis- senting). 1042 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 apply.152 It did so by identifying several key factors, including “intimacy, comprehensiveness, expense, retrospectivity, and voluntariness.”153 The Court distinguished the records in Mil- ler from CSLI, but the financial tools of 1976 are misleading when analogized to modern technology. While those factors aptly distinguish CSLI from checks and deposit slips, they fur- ther muddle Fourth Amendment law when one considers mod- ern financial records. The majority thoroughly explored the comprehensiveness of the location tracking that CSLI provides, since “individuals have a reasonable expectation of privacy in the whole of their physical movements.”154 While favorably comparing CSLI to GPS tracking, they stated “cell phone location information is detailed, encyclopedic, and effortlessly compiled.”155 Although financial records may not produce location data points as fre- quently as CSLI, they may be more precise and reveal more intimate information. Additionally, the cell data at issue in Carpenter was only collected “at call origination and at call termination for incoming and outgoing calls,” which for many people would produce hits less frequently than transaction data.156 CSLI was also accurate to “one-eighth to four square miles,”157 which in a city could cover “several hundred city blocks.”158 A credit card swipe will place you at a particular subway station, or a precise business on a crowded street or in a mall. In Carpenter, CSLI was seen as even more invasive than a GPS monitor placed on a car because a “cell phone faithfully follows its owner beyond public thoroughfares and into private residences, doctor’s offices, political headquarters, and other potentially revealing locales.”159 But a credit card is not left in the car either—it will follow a user into each of those locales. 152 Id. at 2217. 153 Id. at 2234 (Kennedy, J., dissenting). 154 Id. at 2217. 155 Id. at 2216. 156 Id. at 2212. 157 Id. at 2218. 158 Id. at 2225 (Kennedy, J., dissenting). 159 Id. at 2218. No. 2] MILLER IN A CASHLESS SOCIETY 1043 While the card will only ‘ping’ when used, the cell phone in Carpenter only transmitted location data when used for calls.160 Increases in online shopping and donations, and peer- to-peer transfers, mean financial records also provide infor- mation on users who never even leave their homes.161 Furthermore, the majority was concerned with the retro- spectivity of CSLI data. Privacy concerns were higher because the government could “travel back in time to retrace a person’s whereabouts subject only to the [5-year] retention policies of the wireless carriers.”162 Financial data is also kept for years, and like CSLI it can reveal more than just a person’s wherea- bouts. Similarly, authorities do not need to “know in advance whether they want to” investigate an individual using finan- cial records because they can later “call upon the results of that surveillance without regard to the constraints of the Fourth Amendment.”163 While Sprint and Verizon are “[u]nlike the nosy neighbor who keeps an eye on comings and goings, [since] they are ever alert, and their memory is nearly infallible,” so too are Visa and Wells Fargo.164 The Carpenter majority relied on distinguishing the financial records in Mil- ler as “limited types of personal information,” but that descrip- tion no longer holds true.165 The majority also cited the ease of access to those records. They explained that “cell phone tracking is remarkably easy, cheap, and efficient compared to traditional investigative tools. With just the click of a button, the Government can ac- cess each carrier’s deep repository of historical location infor- mation at practically no expense.”166 The same can be said for financial records. When the BSA was created, it was “esti- mated that a minimum of 20 billion checks—and perhaps 30 160 Id. at 2214. 161 See supra Section III.A.1. 162 Carpenter v. U.S., 138 S. Ct. 2206, 2218 (2018). 163 Id. 164 Id. at 2219. 165 Id.; see supra Section III.A.1. 166 Carpenter, 138 S. Ct. at 2217–18. 1044 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 billion—[would] have to be photocopied . . .a year.”167 Now, government authorities can acquire nearly limitless digital fi- nancial data with simple requests to financial institutions.168 The equivalent records used to be physical papers that a bank possessed or, to get a comprehensive view of someone’s fi- nances, personal records kept at home.169 Additionally, much of the data that is present in modern financial records simply would not have existed in the past, since many transactions were in cash.170 Finally, the Court distinguished CSLI from other third- party doctrine cases because the “inescapable and automatic nature of its collection” made it difficult to call the sharing voluntary.171 Since the use of a cell phone was “indispensable to participation in modern society,” it became exempt from the traditional third-party doctrine.172 But having a bank account should “not mean that one has waived all right to the privacy of the papers” either.173 Today, having a bank account is just as essential an activity as owning a cell phone. In 2021, 3% of Americans did not own a cell phone and 4.5% did not have a bank account.174 Even “unbanked” individuals complete transactions that are picked up by our surveillance infrastruc- ture, such as those done through money orders and check cashing. Importantly, in Carpenter the user could not opt out of sharing CSLI, so “there [was] no way to avoid leaving 167 Cal. Bankers Ass’n v. Shultz, 416 U.S. 21, 84 (1974) (Douglas, J., dissenting). 168 See supra Section II.A. 169 “The fact that someone could have tucked a paper bank statement in a pocket does not justify a search of every bank statement from the last five years.” Riley v. California, 134 S. Ct. 2473, 2493 (2014). 170 See supra Section III.A.1. 171 Carpenter, 138 S. Ct. at 2223. 172 Id. at 2220. 173 Cal. Bankers Ass’n, 416 U.S. 21 at 96 (Marshall, J., dissenting). 174 Pew Research Center, Mobile Fact Sheet, PEW RSCH. CENTER (Apr. 7, 2021), https://www.pewresearch.org/internet/fact-sheet/mobile/ [https://perma.cc/YN8J-NA3R]; Federal Deposit Insurance Corporation, 2021 FDIC National Survey of Unbanked and Underbanked Households, FDIC (Jul. 24, 2023), https://www.fdic.gov/analysis/household-survey/in- dex.html [https://perma.cc/5R4K-2P9B]. No. 2] MILLER IN A CASHLESS SOCIETY 1045 behind a trail of location data.”175 If a user could opt out of the BSA’s record retention requirements, surely the option would have been exercised by cartel leaders, fraudsters, and sanc- tioned oligarchs. In 1974, Justice Powell noted that “[a]t some point, govern- mental intrusion upon [financial records] would implicate le- gitimate expectations of privacy.”176 If one focuses on the logic of Carpenter, that time has come. B. The Law Enforcement Tradeoff The financial surveillance infrastructure was built to serve law enforcement purposes and limit the “heavy utilization of our domestic banking system by the minions of organized crime.”177 While that structure undoubtedly raises privacy and constitutional concerns, completely eliminating the BSA and broad subpoena powers for financial information would make “a good deal of white-collar crime” nearly impossible to prosecute.178 In many cases, such as in Miller itself, the government likely had the probable cause required for a warrant.179 A war- rant requirement in those circumstances is simply a proce- dural hurdle. Like any procedural protection, one consequence is added inefficiency. While inefficiency is a feature and not a bug in the domain of the Fourth Amendment,180 law enforce- ment would point to the marginal costs of such a change as a reason to oppose it. Presenting your evidence to a judge for a warrant application takes time—”police must draft affidavits 175 Carpenter, 138 S. Ct. at 2220. 176 Cal. Bankers Ass’n, 416 U.S. at 79 (Powell, J., concurring). 177 Id. at 30; see supra Section II.A. 178 Stuntz, supra note 22, at 863. 179 In Miller, prior to the subpoena for bank records, law enforcement received an informant’s tip that the defendant operated an unlicensed dis- tillery, found incriminating material in a car driven by his coconspirators, and discovered “a 7,500-gallon-capacity distillery, 175 gallons of nontax- paid whiskey, and related paraphernalia” after a fire in his building. United States v. Miller, 425 U.S. 435, 437 (1976). 180 Riley v. California, 573 U.S. 373, 401 (2014). 1046 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 and wait around courthouses.”181 Given that complex white- collar investigations can take months or years, it is hard to see how any short procedural delay would have significant ef- fects on such an investigation. But the effect could be cumula- tive, with countless additional hours spent completing paper- work. More importantly, a probable cause standard for accessing financial records could prevent many white-collar investiga- tions from beginning at all.182 In those cases, authorities heav- ily use subpoenas and “often must examine documents and question witnesses” before establishing probable cause.183 Law enforcement often “subpoena[s] credit card statements to develop probable cause to prosecute” a wide range of crimes, such as “drug trafficking… healthcare fraud [and] tax eva- sion.”184 If warrants were required for digital financial data, it “would be a massive sea-change with untold consequences on investigative possibilities (and a significant disturbance of the equilibrium in favor of the individual).”185 Instead, the government “must have the power to subpoena witnesses and documents before it knows whether those witnesses and doc- uments will yield incriminating evidence” if it is to regulate much of modern business and political affairs.186 For crimes like drug trafficking, where there are often wit- nesses or physical evidence which create suspicion, the sub- poena power may be less necessary. Traditional physical evi- dence and witnesses, along with CTRs and SARs, can alert law enforcement to unusual transaction patterns of cash- based illegal operations. Additionally, “raising the cost of searching” for small-time crimes may be a good idea anyway, 181 Stuntz, supra note 22, at 848. But see Riley, 573 U.S. at 401 (noting that technological advances have also made the process of obtaining a war- rant itself more efficient). 182 Stuntz, supra note 22, at 860. 183 Id. at 859. 184 Carpenter v. U.S., 138 S. Ct. 2206, 2229 (2018) (Kennedy, J., dis- senting). 185 Rosenzweig, supra note 24. 186 Stuntz, supra note 22, at 860. No. 2] MILLER IN A CASHLESS SOCIETY 1047 as it could “improve the allocation of police resources.”187 The subpoena power can also be dangerous because it can allow “prosecutors to invade the privacy of suspects and witnesses without sufficient cause,” and permit “white-collar investiga- tions to run amok.”188 The “almost limitless subpoena power” means overzealous investigators can intrude on “the privacy, time, and energy of suspects and witnesses.”189 Because pros- ecutorial discretion and federal law are so expansive, “if pros- ecutors look hard enough, they can find nearly anyone to have violated” some law.190 While critics of the larger BSA framework contend “money laundering charges tend to be simply added to the main of- fense rather than providing any independent benefit,” this concedes there are added benefits to affirmative reporting.191 Indeed, FinCEN highlights examples of CTRs or SARs which began or expanded investigations resulting in significant criminal sanctions.192 Multiple fraud schemes against the pandemic Paycheck Protection Program unraveled after the filing of single SARs.193 Further investigation led authorities to recover millions of dollars and charge multiple individu- als.194 Other notable cases involved BSA reports starting in- vestigations into securities fraud, drug trafficking, and 187 Id. at 849. 188 Id. at 843. 189 Id. at 861, 864. 190 Id. at 864. See also Robert H. Jackson, The Federal Prosecutor, ROB- ERT H. JACKSON CTR., https://www.roberthjackson.org/speech-and-writ- ing/the-federal-prosecutor/ [https://perma.cc/LYG6-2H5U] (last visited Sept. 15, 2023). 191 Michel & Schulp, supra note 55, at 10 (emphasis added). 192 Annual FinCEN Program Recognizes Law Enforcement Cases Sup- ported by BSA Data, FINCEN (Dec. 7, 2022), https://www.fin- cen.gov/news/news-releases/annual-fincen-program-recognizes-law-en- forcement-cases-supported-bsa-data [https://perma.cc/24C2-MZ6P]. 193 Compilation of Award Recipient & Nominated Cases, FINCEN (Jan. 9, 2023), https://www.fincen.gov/sites/default/files/shared/Compila- tion%20of%20Award%20Recipient%20and%20Nomi- nated%20Cases%20FINAL%20508C.pdf [https://perma.cc/MR5K-RWZS]. 194 Id. 1048 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 healthcare fraud.195 The reports also proved vital in prose- cuting firearms trafficking, Ponzi schemes, and violations of non-proliferation sanctions.196 After using financial infor- mation to build probable cause, search warrants were exe- cuted in many of these cases to gather physical evidence of the crimes. However, those narratives from FinCEN are still akin to the anecdotes of pre-BSA activity which supposedly necessi- tated its creation.197 Individual cases are necessarily limited in providing information on the overall value of the financial surveillance system. It is difficult to do a more thorough cost- benefit analysis on affirmative reporting because law enforce- ment agencies do not track the usefulness of SARs and CTRs.198 Scholars have attempted to do so without much suc- cess,199 and some in Congress have “repeatedly asked the Treasury and FinCEN for evidence—not merely anecdotes about enforcement actions—that the AML regime provides a net benefit.”200 This regime’s compliance costs, excluding enforcement by the Department of Justice and Internal Rev- enue Service, “are estimated to be between $4.8 billion and $8 195 Id. 196 Id. 197 Michel & Schulp, supra note 55, at 4. Both the 1968 and 1969 hearings relied on little more than govern- ment officials’ anecdotes and assurances that access to more infor- mation was essential to effective law enforcement. None of the wit- nesses provided data to support the prevalence of the ostensible money laundering problems through either domestic or foreign fi- nancial institutions. Moreover, the witnesses barely discussed how the specific legislative proposals for domestic transactions might im- prove the ability to prosecute crimes. 198 U.S. GOV’T ACCOUNTABILITY OFF., GAO-22-105242, BANK SECRECY ACT: ACTION NEEDED TO IMPROVE DOJ STATISTICS ON USE OF REPORTS ON SUSPICIOUS FINANCIAL TRANSACTIONS 2 (2022). 199 Lanier Saperstein, Geoffrey Sant & Michelle Ng, The Failure of Anti-Money Laundering Regulation: Where is the Cost-Benefit Analysis?, 91 NOTRE DAME L. REV. ONLINE 1, 1–2, 11 (2015); Ronald F. Pol, Anti-Money Laundering: The World’s Least Effective Policy Experiment? Together, We Can Fix It, 3 POLICY DESIGN AND PRACTICE 73 (2020). 200 Michel & Schulp, supra note 55, at 10 (emphasis added). No. 2] MILLER IN A CASHLESS SOCIETY 1049 billion annually.” 201 If, as Congressman McHenry argues, the benefits provided “[do] not justify the [financial] burden placed on small businesses,” how do they justify the privacy consequences for individuals?202 As discussed in Section III.A, the transition to a cashless society is likely inevitable, raising concerns about government agents’ access to the data produced by mass surveillance. Pri- vacy advocates are right to push back on the constant ratch- eting up of financial surveillance and question its benefits. But without strong evidence that it is wholly ineffective, we must also keep in mind the real public interest in combatting organized crime, terrorist financing, and other illicit activi- ties. While law enforcement’s unrestricted access to the prod- ucts of financial surveillance should be limited, a complete warrant requirement could allow financial records to “become a protected medium that dangerous persons will use to com- mit serious crimes.”203 C. “No Single Rubric” will Resolve these Issues in the Courts Two alternate approaches to Fourth Amendment cases are originalism and the mosaic theory. Originalism has been ap- plied widely to issues facing federal courts, but it has not been prevalent in this space. Meanwhile, the mosaic theory, which understands quantitative privacy in ways categorical tests do not, could offer an interesting framework for modern, data- driven searches. However, for reasons both doctrinal and practical, neither provides a sweeping solution to privacy con- cerns about searches of financial records. 201 Norbert Michel and David Burton, Financial Privacy in a Free So- ciety, THE HERITAGE FOUND. (Sept. 23, 2016), https://www.heritage.org/mar- kets-and-finance/report/financial-privacy-free-society/#_ftn1 [https://perma.cc/KV6V-RRUW]. 202 Michel & Schulp, supra note 55, at 10. 203 Carpenter v. U.S., 138 S. Ct. 2206, 2230 (2018) (Kennedy, J., dis- senting). 1050 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 1. Differing Originalist Conceptions of the Fourth Amendment While originalism may currently reign supreme as a con- stitutional interpretive method, it is not quite clear what originalism as applied to searches of financial records would look like. In separate dissents in Carpenter, Justices Thomas, Alito, and Gorsuch offered their approaches to the Fourth Amendment issues raised. The main issue with applying originalism to Fourth Amendment cases is that there is “limited source material.”204 A committed originalist cannot look to debates in Congress over the amendment because there were “virtually [none].”205 “[T]he Supreme Court did not directly address the meaning of searches for nearly 100 years,” so looking to early case law is also unhelpful.206 The way courts approached broader Fourth Amendment cases has changed too, limiting their use for in- sight into the original meaning of the text. Since “early cases involved a physical violation of the home or other property,” there was obviously a search and courts were concerned with reasonableness.207 Now, when the whole question is whether something is a search or not, those cases “[do] not give mean- ingful guidance for the myriad technological advances in in- vestigatory techniques.”208 In Carpenter, Justice Thomas argued for a property-based reading of the Fourth Amendment, which would be incompat- ible with the existence of the Katz test.209 He stated that the Fourth Amendment aims to protect property, and it protects 204 Michael Gentithes, Rulifying Reasonable Expectations: Why Judi- cial Tests, Not Originalism, Create A More Determinate Fourth Amendment, 59 HOUS. L. REV. 1, 18 (2021). 205 Id. at 19. 206 Id. 207 Id. at 17. 208 Id. 209 Carpenter v. U.S., 138 S. Ct. 2206, 2238–39 (2018) (Thomas, J., dis- senting). No. 2] MILLER IN A CASHLESS SOCIETY 1051 privacy only in a derivative manner.210 To him, Katz distorts the original meaning of the Fourth Amendment.211 The sec- ond Katz prong, whether society is prepared to recognize the subjective privacy belief as reasonable, can of course change over time, even by government influence.212 He argued that a search should not be defined by whether an expectation of pri- vacy was violated, but by its ordinary definition of looking or examining “for the purpose of finding something.”213 From this starting point, financial records requests could qualify as searches. Government authorities surely request them for the purpose of examining their contents for traces of illegal activity. However, Justice Thomas also noted that “a subpoena for third-party documents” is not a search.214 On that point, Justice Alito agreed, writing separately that “an order to produce” is wholly different than a search, and that “the Fourth Amendment, as originally understood, did not ap- ply to the compulsory production of documents at all.”215 Fur- thermore, he concluded that the Fourth Amendment focused on the means of production, and records requests to third par- ties are not nearly as invasive as physical searches.216 For fi- nancial records, the inquiry would seem to end there. Both justices would likely agree that judicial subpoenas for finan- cial records do not count as searches and therefore the Fourth Amendment is not implicated. An originalist reading of the Fourth Amendment would also focus on “whose property was searched.”217 In Carpenter, the originalists argued there was not a property interest be- cause the defendant “did not create the records, he does not maintain them, he cannot control them, and he cannot destroy them.”218 This is similar to the third-party doctrine and would 210 Id. at 2240. 211 Id. at 2238, 2241–43. 212 Id. at 2245. 213 Id. at 2238. 214 Id. at 2244. 215 Id. at 2247–50 (Alito, J., dissenting). 216 Id. at 2251–52. 217 Id. at 2235 (Thomas, J., dissenting) (emphasis in original). 218 Id. 1052 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 also likely cut against protection for modern financial records. Justice Thomas wrote that the Court has “not acknowledged that individuals can claim a reasonable expectation of privacy in someone else’s business records.”219 Justice Alito added that the third-party doctrine simply effectuates the “their” in the Fourth Amendment, which concentrates the inquiry on who owns the item being searched.220 While Justice Gorsuch agreed that subpoenas should be al- lowed for “ordinary business records,” he was more receptive to an individual having property rights in certain data en- trusted to third parties.221 In signaling a desire to scrap the third-party doctrine altogether, he commented that if the Katz test is still good law, “no one believes that” we don’t actually have expectations of privacy in our private documents resid- ing with third parties.222 While also applying a property- based conception to the Fourth Amendment, he concluded that related law has not developed a sufficient answer for when digital data is “yours.”223 The originalists may therefore proceed differently in a property-interest analysis of financial records. All three of these Justices concurred that positive law can be used to cre- ate a property interest and therefore a Fourth Amendment in- terest.224 But Justice Gorsuch noted third-party access need not eliminate one’s property interest in their papers and ef- fects, and that exclusive control or ownership may not be needed to create a Fourth Amendment interest.225 He pon- dered whether the “demands of modern life” mean that the 219 Id. at 2242. 220 Id. at 2260 (Alito, J., dissenting). 221 Id. at 2271 (Gorsuch, J., dissenting). 222 Id. at 2262. 223 Id. at 2268. “Just because you entrust your data—in some cases, your modern-day papers and effects—to a third party may not mean you lose any Fourth Amendment interest in its contents.” Id. at 2269. 224 Id. at 2240–42 (Thomas, J., dissenting), 2251–52, 57–60 (Alito, J., dissenting), 2267–71 (Gorsuch, J., dissenting). 225 Id. at 2268–70. “Where houses are concerned, for example, individ- uals can enjoy Fourth Amendment protection without fee simple title . . . tenants and resident family members—though they have no legal title— have standing to complain about searches of the houses in which they live.” No. 2] MILLER IN A CASHLESS SOCIETY 1053 way “we store data with third parties may amount to a sort of involuntary bailment too.”226 Therefore, in Carpenter, Justice Gorsuch thought it possi- ble that the CSLI did belong to the defendant.227 The “sub- stantial legal interests” he had through positive law could be enough to create a property right, even though the corporation held the information.228 Applying Justice Thomas’s reasoning, any statutory hook for a property interest in financial records would be limited by the RFPA itself, which allows warrantless requests for financial records. Additionally, Justice Alito spe- cifically noted that many statutes, including the RFPA, grant rights to customers “without creating any property right.”229 The BSA’s rules also show that “customers do not create the records; they have no say in whether or for how long the rec- ords are stored; and they cannot require the records to be mod- ified or destroyed.”230 But Justice Gorsuch further noted “there may be some cir- cumstances where positive law cannot be used to defeat” prop- erty interests.231 For example, Congress could not defeat Fourth Amendment interests of individuals by requiring the post office to read every letter.232 Justice Gorsuch, therefore, would not give Congress’s creation of the BSA as much weight in considering the Fourth Amendment interests in our finan- cial transactions.233 In not only protecting “the specific rights known at the founding,” but “their modern analogues too,” Justice Gorsuch may be sympathetic to the idea that modern 226 Id. at 2270. 227 Id. at 2272. 228 Id. 229 Id. at 2257 n.3 (Alito, J., dissenting). 230 Id. at 2229 (Kennedy, J., dissenting). 231 Id. at 2270 (Gorsuch, J., dissenting). 232 Id. 233 See United States v. Miller, 425 U.S. 435, 442–43 (1976). The lack of any legitimate expectation of privacy concerning the in- formation kept in bank records was assumed by Congress in enact- ing the Bank Secrecy Act, the expressed purpose of which is to re- quire records to be maintained because they “have a high degree of usefulness in criminal tax, and regulatory investigations and pro- ceedings.” (internal citation omitted). 1054 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 financial transactions contain information that was tradition- ally within one’s papers.234 If so, he explained that subpoenas could not then be used to evade constitutional protections.235 At the moment, there does not appear to be a consensus originalist approach to this issue that would have the neces- sary votes at the Supreme Court, if the Court were to even take another Fourth Amendment case soon. As such, the methodology does not currently solve the “indeterminacy” in Fourth Amendment jurisprudence.236 Additionally, an originalist approach that considers traditional property rights and other positive law may simply end up back at Miller, prov- ing unhelpful for privacy advocates’ policy goals. 2. Mosaic Theory and Judicial Line Drawing The mosaic theory is the approach most apt to protect pri- vacy interests in financial records. However, its critics con- tend that the approach would, at best, sacrifice consistency and efficiency for accuracy. The mosaic theory rejects a categorical approach to searches and instead focuses on the amount and type of infor- mation collected.237 It argues that, at a certain point, a large quantity of data paints a picture that is “qualitatively differ- ent” than the same search technique in smaller doses.238 In this way, it aligns best with the privacy interests at issue in large volumes of financial records. Unlike a search of a house on one occasion, a query of an individual’s financial transac- tions from one day may not reveal copious information. How- ever, that same financial records search could reveal a de- tailed view of an individual’s life if sufficiently expanded, as “[a]ggregations of data create information beyond their 234 Carpenter, 138 S. Ct. at 2271 (Gorsuch, J., dissenting). 235 Id. Justice Gorsuch notes that even if the Fourth Amendment did not cover this issue, the Fifth Amendment would likely be implicated as a right against self-incrimination was recognized at the time of the founding. 236 Gentithes, supra note 204, at 28. 237 See Rosenzweig, supra note 24. 238 Id. “[A] single piece of tile in a mosaic is just a single tile with a single color, that tells you nothing. But if you collect enough tiles, put them in a pattern, and step back, you can see a beautiful Roman mosaic.” No. 2] MILLER IN A CASHLESS SOCIETY 1055 individual value.”239 Advertisers and political campaigns al- ready believe this to be true—they target outreach based on it.240 Applying the mosaic theory to financial records searches could protect against warrantless reviews that are long-term and reveal particularly sensitive information. At the same time, smaller pieces of financial data would still be accessible without a warrant. While the mosaic approach has not been accepted by many courts, in recent years some have experimented with applying it to new technologies.241 In Commonwealth v. Henley and Commonwealth v. McCarthy, the Massachusetts Supreme Court openly embraced the mosaic theory.242 McCarthy con- cerned cameras on a Cape Cod bridge, which created a com- prehensive record of vehicles traveling over it.243 Police used the cameras to track a drug trafficking suspect’s car in real- time, and they also searched the historical data.244 The court reasoned that widespread use of such technology could cer- tainly constitute a search, but the use of four cameras on two bridges was limited surveillance that did not capture “suffi- ciently detailed” information to require a warrant.245 Deploy- ing similar logic, in Henley the court rejected the wholesale application of the third-party doctrine to metro cards and de- cided that an extensive search of those records for location his- tory could constitute a search under the mosaic theory.246 However, “whether the aggregation of data collected by police implicates the mosaic theory depends on how much data police 239 Id. 240 Id. 241 It was also used by the D.C. Circuit in the case that became United States v. Jones, but the Supreme Court upheld that ruling on a property- based conception of the Fourth Amendment. See United States v. Maynard, 615 F.3d 544, 562–63 (D.C. Cir. 2010) (finding that the “whole of one’s move- ments over the course of a month . . . reveals far more than the individual movements it comprises.”). 242 Commonwealth v. Henley, 488 Mass. 95 (2021); Commonwealth v. McCarthy, 484 Mass. 493 (2020). 243 McCarthy, 484 Mass. at 495. 244 Id. at 494–97. 245 Id. at 505–09. 246 Henley, 488 Mass. at 95. 1056 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 retrieved and the time period involved,” and two days’ worth of data was not a search.247 In another transit-related case, police used video surveil- lance to determine which metro card an armed robber was as- sociated with.248 They then set up an alert for that card’s fu- ture access to the system, which later notified them of his location and lead to his arrest.249 The court relied on Henley and concluded that the information gathered during this two- day tracking was limited, so the use of the subject’s location data was not a search in this case.250 Meanwhile, the Seventh Circuit walked through an application of the mosaic theory in a drug trafficking case where long-term video surveillance was employed, but it cautioned that it was not accepting the approach yet.251 The court determined that even if it accepted a mosaic approach, 18 months of video surveillance directed at a subject’s home would not be a search because it was tar- geted and did not reveal the “businesses he frequented, with whom he interacted in public, or whose homes he visited, among many other intimate details of his life.”252 The mosaic theory is not without its critics, however.253 The theory would be quite hard to administer, especially as technological changes move faster than judges can “resolve how to regulate them.”254 Law enforcement would lack clear guidance to know when they need to request a warrant. Judges would be left to individually weigh duration, content, platform, and other considerations, with results that may vary greatly between courts. This contrasts with criminal 247 Id. at 110, 113–14. 248 Kelly v. United States, 281 A.3d 610, 613 (D.C. Cir. 2022). 249 Id. 250 Id. at 614–15. 251 United States v. Tuggle, 4 F.4th 505 (7th Cir. 2021), cert. denied, 142 S. Ct. 1107 (2022). 252 Tuggle, 4 F.4th at 524. 253 Orin S. Kerr, The Mosaic Theory of the Fourth Amendment, 111 MICH. L. REV. 311 (2012). 254 Id. at 347. No. 2] MILLER IN A CASHLESS SOCIETY 1057 law’s usual prioritization of certainty for police, who “must act before they know whether they have guessed right.”255 Uncertainty is especially bad in the Fourth Amendment context because of exclusionary and immunity rules—if police err innocently, our legal system generally does not want them liable for significant damages or for defendants to be unjustly freed.256 Regarding the exclusionary rule, there are questions of whether it would even apply to mosaic theory cases and, if not, whether that would lead to more inconsistencies.257 Ad- ditionally, courts applying “mosaic protection complicate the legislative picture” by effectively preempting action which would regulate new technologies’ capability for privacy in- fringement.258 If a court imposes “an arbitrary and outside limit,” it “closes off further legislative debate on these is- sues.”259 While certainty is favored, courts in criminal proce- dure have almost always avoided setting bright-line dura- tional limits.260 Fourth Amendment jurisprudence should protect values besides consistency, but critics are ultimately correct that the mosaic approach is not a sustainable method of Fourth Amendment jurisprudence. If the theory is effectively “more legislating than interpreting anything in the Constitution,” it would make more sense for Congress to take the reins.261 255 Stuntz, supra note 22, at 867. 256 Gentithes, supra note 204, at 37–38. 257 Kerr, supra note 253, at 340–42, 346. 258 Id. at 351. 259 Carpenter v. U.S., 138 S. Ct. 2206, 2233 (2018) (Kennedy, J., dis- senting). 260 See Rosenzweig, supra note 24. 261 Orin Kerr, Four Thoughts on the Briefing in Carpenter v. United States, LAWFARE (Nov. 17, 2017), https://www.lawfaremedia.org/arti- cle/four-thoughts-briefing-carpenter-v-united-states [https://perma.cc/2UL3-EPLN]. See also Carpenter, 138 S. Ct. at 2233 (Ken- nedy, J., dissenting). 1058 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 IV. A. Congressional Checks on Financial Records Searches It would be very unfortunate if privacy protection in the 21st century were left primarily to the federal courts using the blunt instrument of the Fourth Amendment. Legislatures, elected by the people, are in a better position than we are to assess and respond to the changes that have already occurred and those that almost certainly will take place in the future.262 While, even after Carpenter, courts are very unlikely to overturn Miller,263 the reality of easy government access to increasingly comprehensive financial records should spur Congressional action. Vast databases of financial data are available on nearly all Americans,264 and the constitutional rationales for that data being unprotected are now doctrinally weak.265 This Note does not purport to resolve the complicated issue it recognizes. Rather, it discusses the real tradeoffs and merely offers a few potential mitigating policies below. 1. Time Constraints Currently, subpoenas and other procedures for govern- ment access to financial records are not limited in scope by statute.266 Congress can mimic the intent of a mosaic theory, while providing certainty to law enforcement, through a bright-line durational rule. 262 Riley v. California, 573 U.S. 373, 408 (2014) (Alito, J., concurring). 263 See supra Section II.B. 264 See supra Section III.A.1. 265 See supra Section III.A.2. 266 While summonses and subpoenas can be ruled overbroad, defend- ants often do not have an incentive or opportunity to challenge them, as noted in Section IV.A.2. Additionally, due to the long-term nature of many alleged schemes, financial records requests that span months or years may actually be relevant to an investigation. No. 2] MILLER IN A CASHLESS SOCIETY 1059 Courts have a “general preference to provide clear guid- ance to law enforcement through categorical rules,”267 and the rule from Miller is undoubtedly clear. However, the Fourth Amendment’s other values are now in sharp conflict with that rule. As Professor Kerr notes, “when technology is new or in flux, and its use may have privacy implications far removed from property law, Fourth Amendment rules alone will tend not to provide adequate privacy protections.”268 While finan- cial records are not a wholly new data form, the technologies which feed into them are new and still developing. Accordingly, Congress should enact a durational limit for requests of financial records under The Right to Financial Pri- vacy Act.269 Sections that authorize access through con- sent,270 administrative subpoena,271 judicial subpoena,272 and written request 273 already contain criteria for their applica- bility. A limit set between two to four weeks would protect against long-term surveillance access, which produces the most serious privacy concerns.274 “The potential for abuse is particularly acute where” there is access to financial “infor- mation without invocation of the judicial process,” and current law does not require any invocation of such process.275 By re- quiring that “a neutral magistrate” scrutinize every request for probable cause once it goes beyond the durational limit, Congress would restore some balance between the “societal and individual interests” at play here.276 267 Riley, 573 U.S. at 398. 268 Orin S. Kerr, The Fourth Amendment and New Technologies: Con- stitutional Myths and the Case for Caution, 102 MICH. L. REV. 801, 809 (2004). 269 Search warrants under § 3406 would not be impacted. 270 12 U.S.C. § 3404. 271 12 U.S.C. § 3405. 272 12 U.S.C. § 3407. 273 12 U.S.C. § 3408. 274 See supra Sections III.A, III.B. 275 Cal. Bankers Ass’n v. Shultz, 416 U.S. 21, 79 (1974) (Powell, J., con- curring). 276 Id. 1060 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 While some advocate for a total warrant requirement,277 limited-duration financial records searches are not as inva- sive. Shorter collection periods limit the privacy consequences of data aggregation, as fewer inferences can be drawn from less encyclopedic information.278 Surely, even one day of fi- nancial transactions could reveal very private information. But even in the pre-digital age, a member of law enforcement may have seen what religion a target belongs to, who their friends are, which political party they support, and various purchases they make just by shadowing them. A time con- straint on warrantless review of financial data would allow authorities to build probable cause over a period when privacy concerns are less implicated. More extreme measures, such as a warrant requirement or a much shorter duration require- ment, would make prosecuting many white-collar crimes nearly impossible.279 This change would not impact the filing of BSA reports. Law enforcement would still receive SARs and CTRs and use them to begin or augment investigations. Probable cause for a wide-ranging search of financial records may exist at that stage. If not, financial data gathered during the circumscribed request period and traditional evidence from confidential in- formants, anonymous tips, and direct observation would sup- plement each other. If probable cause for a search of physical properties or email contents is not met at that point, a com- prehensive search of a target’s financial records should not proceed either. This framework could limit fishing through an individual’s financial records in search of a crime. Addition- ally, this change only protects individuals—the RFPA would still not cover corporations or partnerships of more than five individuals.280 277 Michel & Schulp, supra note 55. 278 See James G. McLeod, All Things in Aggregation: Reassessing the Fourth Amendment’s Third-Party Doctrine and the Fourth Circuit’s Ap- proach to Cell Site Location Information in United States v. Graham, 96 N.C. L. REV. 1203, 1213 (2018); see also Kerr, supra note 253, at 313. 279 See supra Section III.B. 280 12 U.S.C. § 3401(4)-(5). No. 2] MILLER IN A CASHLESS SOCIETY 1061 There are certainly other issues to be worked out with this approach. Would law enforcement be able to string together one-month subpoenas in order to get a comprehensive look at one’s records? Or, if they request a subpoena against an indi- vidual any time after they already used the one-month look, does the bar still apply years later? What if coordinating au- thorities get subpoenas that cover different time periods, and then share information? This Note does not purport to craft a perfect solution but merely offers one proposal that attempts to assuage privacy concerns while realizing that “privacy comes at a cost.”281 2. Suppression as a Remedy under the RFPA Alternatively, or in conjunction with the above proposal, Congress should add suppression as a remedy for violations of the RFPA and similar statutes. If we are to accept lesser stat- utory protections in place of full Fourth Amendment coverage for financial data, there need to be real consequences for breaches of such protections. Suppression of evidence is not a remedy for violations of the RFPA.282 The statute provides for monetary damages,283 injunctive relief,284 and, in cases of willful or intentional vio- lations, disciplinary action.285 Since exclusion is not explicitly included, when defendants have tried to challenge the use of seized financial records under the RFPA, courts have plainly held that any statutory violation “is insufficient to justify the 281 Riley v. California, 573 U.S. 373, 401 (2014). 282 United States v. Kington, 801 F.2d 733, 737 (5th Cir. 1986); United States v. Davis, 953 F.2d 1482, 1496 (10th Cir. 1992); see also U.S. Dep’t of Just., Crim. Res. Manual § 440. 283 12 U.S.C. § 3417(a). Plaintiffs are entitled to $100, plus actual dam- ages. 284 12 U.S.C. § 3418. Note that injunctive relief consists of an order that the government, for example, provide notice the next time it requests a spe- cific defendant’s financial records. Botero-Zea v. United States, 915 F. Supp. 614, 620 (S.D.N.Y. 1996). 285 12 U.S.C. § 3417(b). There appear to be no reported cases where a party was disciplined under this provision. 1062 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 exclusion of any evidence.”286 Similarly, the Patriot Act’s fi- nancial records request provisions provide only damages as a remedy for violations.287 Since exclusion of evidence is not a remedy under the RFPA, a defendant must show that the government’s request “violated the Fourth Amendment to warrant suppression of evidence.”288 But according to current case law,289 searches of financial records never violate the Fourth Amendment. There- fore, evidence obtained illegally under the RFPA may still be used at a criminal trial or regulatory hearing. As a result, de- fendants have little incentive to litigate the scope of their rights under the RFPA.290 To summarize, an administrative subpoena or written re- quest for financial records can be issued under a standard of “relevant” to an investigation.291 Such subpoena or request does not require sign-off by a neutral magistrate, and notice can be delayed to the target of the investigation.292 Then, even if a defendant successfully challenges any deviation from those already thin procedural protections, the evidence may still be used against them.293 While subjects have a right to 286 United States v. Thompson, 936 F.2d 1249, 1251 (11th Cir. 1991). 287 Brantley v. Fla. Att’y Gen., No. 19-13214, 2021 WL 3077017, at *7 (11th Cir. July 21, 2021), cert. denied sub nom. Brantley v. Moody, 142 S. Ct. 2723, 2723 (2022), reh’g denied, 143 S. Ct. 57, 57 (2022). This was a child exploitation case where agents used the Patriot Act, likely Section 314, to discover the defendant used an American Express account, and then in- voked it again to request the defendant’s financial information from Amer- ican Express. This Note’s proposed changes would not result in suppression in this case, as a judge viewing the facts could determine that exigent cir- cumstances necessitated prompt discovery of the defendant’s hotel rooms. 12 U.S.C. § 3417(c), which provides for a good-faith defense to RFPA viola- tions, would also remain. 288 United States v. Cray, 450 F. App’x 923, 931 (11th Cir. 2012). 289 See supra Section II.B. 290 See supra notes 282–85. 291 12 U.S.C. §§ 3405, 3408. Investigators only need a reason to believe the records are relevant, which would “permit access where the only infor- mation available is an anonymous tip.” U.S. Dep’t of Just., Crim. Res. Man- ual § 413. 292 12 U.S.C. § 3409. 293 See supra note 282. No. 2] MILLER IN A CASHLESS SOCIETY 1063 challenge a subpoena if notified,294 when notice is not given before the subpoena is completed, the ability to quash it is moot.295 So, if the delay provision is invoked, the subject loses any ability to stop their financial records from being turned over and used by the government. Congress should close this loophole by adding suppression of evidence as a remedy under 12 U.S.C. § 3417.296 3. Reforming Mandatory Reporting The heart of the BSA is the system of mandatory retention and reporting by financial institutions. While reforming the reporting of CTRs and SARs is a complicated issue that is much too large for detailed discussion within this student Note, addressing it would reduce the privacy concerns dis- cussed here. Some advocates have questioned whether CTRs are even necessary because truly suspicious information should be cov- ered by the SAR process.297 Other advocates urge that SAR reporting itself be discontinued.298 The government receives many more SARs than are needed; institutions are incentiv- ized to over-file, and in the process, they effectively accuse their customers of wrongdoing to the government.299 Manda- tory reporting has become much more extensive because re- ports have not been adjusted for inflation, regulators’ aggres- sive stance has encouraged defensive filings, and laws have 294 12 U.S.C. § 3410. They must move to challenge within 10 days from receipt of notice or 14 days from its mailing date. 12 U.S.C. § 3405(3). 295 See Botero-Zea v. United States, 915 F. Supp. 614, 614 (S.D.N.Y. 1996). 296 The RFPA only applies to federal investigations. As such, the pro- posals in this Section and Section IV.A.1 are inapplicable at the state and local level, which is concerning because of the larger volume of investiga- tions and higher likelihood of politicization there. However, Congress may be able to preempt state law on this issue in regard to interstate financial institutions. 297 Michel & Burton, supra note 40. 298 Michel & Schulp, supra note 55. 299 See supra note 44. 1064 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023 brought more businesses under the umbrella of “financial in- stitution.”300 However, law enforcement does use SARs to hold bad ac- tors accountable.301 Scrapping the whole system, even if the evidence is unclear as to its effectiveness, would not be pru- dent. Reforming the SAR process to discourage defensive fil- ing is a complicated issue that would likely necessitate leni- ency from regulators. If it can be accomplished, it would limit the regulatory burden on financial institutions, reduce inno- cent transactions reported to the government, and better focus law enforcement’s resources. V. CONCLUSION Since the BSA was enacted, successive laws have marched forward in one direction, adding new reports, covered institu- tions, and other requirements. At the same time, changes in technology and consumer habits have greatly increased the proportion of transactions that are recorded and retained. The resulting financial surveillance system contains comprehen- sive and intimate information about nearly every American. While a complete warrant requirement to view any finan- cial data would end many legitimate investigations before they begin, a measured approach would allow law enforce- ment to build support for a finding of probable cause. Access to a subject’s comprehensive financial information, spanning years across all platforms, should be restricted until a stand- ard higher than “relevant” is met and approved by a judge. Breaches of these lesser statutory protections should still come with the exclusionary rules that accompany Fourth Amendment violations. Congress can balance the competing concerns in this area and, for the first time in decades, turn back the dial on finan- cial surveillance.302 In a cashless society where massive troves 300 See supra Section II.A. 301 See supra Section III.B. 302 While a Central Bank Digital Currency is rightly feared for its po- tential surveillance capabilities, a legislative push to implement one may be a unique opportunity for privacy advocates to leverage their votes to raise No. 2] MILLER IN A CASHLESS SOCIETY 1065 of financial data can reveal our most intimate matters, we should reconsider the procedures for access and use by gov- ernment agents. To wait to do so risks keeping the door open “to a vast and unlimited range of very real abuses of police power.”303 the standards for law enforcement access of financial data. Substantial pro- tections on existing financial records, which already enable troubling sur- veillance possibilities, may be unlikely to be independently imposed. 303 United States v. Miller, 425 U.S. 435, 451 (1976) (Brennan, J., dis- senting) (quoting Burrows v. Sup. Ct., 13 Cal. 3d 238 (1974)). 1066 COLUMBIA BUSINESS LAW REVIEW [Vol. 2023