by Lily Van Petten*

This Contribution argues that the sweeping data retrievals conducted via geofence warrants constitute Fourth Amendment searches for purposes of constitutional protections. The Fourth Circuit’s en banc decision in United States v. Chatrie avoided a definitive holding as to whether these investigatory tools pass constitutional muster. The court merely affirmed the district court’s holding that despite the occurrence of a Fourth Amendment violation, evidence would not be suppressed in the defendant’s criminal trial due to the good faith efforts of the investigating officers. The Fourth Circuit should have conclusively held that law enforcement’s use of a geofence warrant constitutes a search because individuals have a reasonable expectation of privacy in their location data under the Supreme Court’s decision in Carpenter v. United States, regardless of the fact that users share that data with third parties. As a result, a particularized search warrant stating probable cause must be obtained for each stage of data acquisition facilitated by a geofence warrant.

More than 91% of Americans own a smart phone.1 Given their massive utility for safety, social engagement, and everyday convenience purposes, it is no surprise that 79% of adults report at least some use of location sharing features on those devices.2 However, users are seldom informed of the sheer quantity of personal data that will be passively transmitted to third-party servers by these features.3 The Fourth Amendment, which protects the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures,” is the mechanism that prevents the government from having unfettered access to the location data of private citizens.”4 At the time of the country’s founding, the Framers could not have conceived of the technologies that can be harnessed today to surveil private life.5 Because the Fourth Amendment is “to be construed in the light of what was deemed an unreasonable search and seizure when it was adopted,” courts have struggled considerably in applying Fourth Amendment doctrine to these increasingly sophisticated technologies.6 Nevertheless, the past two decades have shown a steady expansion of the Supreme Court’s definition of a Fourth Amendment search. This development began with the Court’s recognition that scanning a suspect’s home with a thermal imaging device from the street and placing a GPS tracking device on a suspect’s car were each a search.7 The definition was then expanded to include the contents of a suspect’s smartphone in 2014, and a defendant’s cell-site location information held by cell service providers in 2018.8

A new technology has emerged as the next test of this doctrinal expansion: geofence warrants. Geofence warrants are a major mechanism by which law enforcement can acquire personal information about criminal suspects, identify them, and establish their connection to a crime.9 Law enforcement presents these warrants to technology service providers, such as Google, Apple, Lyft, Snapchat, or Uber, to compel them to retroactively produce the location data of all users whose location was recorded within a particular geographic area—known as a geofence—where and when a crime occurred.10 Google is, by far, the most common recipient of these requests, in part due to the widespread use of Google services and the fact that Google is “the only one known to respond” to law enforcement inquiries.11 As a result, Google is the primary subject of the legal discourse surrounding geofence warrants. This Contribution argues that the acquisition of geofence data from any third-party service provider, Google included, is a search under the Fourth Amendment. Nevertheless, geofence warrants are viable tools that need not be declared categorically unconstitutional, but rather require more robust judicial oversight procedures to pass muster under the Fourth Amendment.

The Fourth Circuit was tasked with examining the constitutionality of data acquisition by geofence warrant in United States v. Chatrie.12 In 2019, after observing surveillance footage of a masked perpetrator committing a bank robbery, Virginia police obtained a geofence warrant and requested user data from Google—which Google collects through its “Location History” feature—of all users for a one-hour period within a 150-meter radius of the bank.13 The search resulted in the identification of Okello Chatrie, who was subsequently charged.14

The technical process by which geofence warrants are processed is critical to the constitutionality question. At Google, geofence warrants are executed by way of a three-step “anonymization and narrowing protocol” that the company developed with advisement from the Department of Justice.15 The process begins with law enforcement determining the appropriate geofence parameters.16 A search warrant is prepared to search Google’s database for the data of users within that geofence.17 Once approved by a magistrate judge, the warrant is sent to Google to search the database, which houses the data of the 592 million users who are opted into Location History sharing.18 Google compiles a list of users whose data match the search criteria, anonymizes the user identities, and shares the list with law enforcement (“Step One”).19 The Step One search in Chatrie returned the Location History data of nineteen users.20

Law enforcement reviews the Step One list and requests that certain users be included in an expanded search, typically of a wider time frame and geographic scope.21 In Chatrie, law enforcement requested additional results for nine of the nineteen Step One users, with no explanation as to how these individuals were chosen from the list, nor additional review by a magistrate judge for this secondary search.22 Google returned the additional anonymized data (“Step Two”).23

From this expanded dataset, officers then request the identity of certain users of interest, which Google provides (“Step Three”).24 The detectives in Chatrie requested de-anonymized data of three of the nine Step Two users, again with no explanation as to how those three were selected, nor with any further approval by a magistrate judge.25 From the Step Three list, Chatrie was identified and ultimately convicted of the bank robbery.26

Although this procedure requires Google to transmit ample user data to the government at three discrete times, only one search warrant is used to facilitate all three steps. The District Court for the Eastern District of Virginia held that the geofence warrant used to identify Chatrie plainly violated his Fourth Amendment rights because the warrant lacked particularized probable cause to collect the data of any person within the geofence.27 However, the data linking Chatrie to the robbery was introduced to his detriment under the good faith exception, which permits the use of evidence seized by officers who reasonably rely on a search warrant, even if the evidence would otherwise be suppressed for having been acquired improperly.28 The Fourth Circuit affirmed on the faulty grounds that the use of the geofence warrant was not a search because Chatrie had relinquished his expectation of privacy by voluntarily sharing his data with Google.29

Shortly thereafter, the Fourth Circuit reheard both the question of whether the acquisition of Chatrie’s Location History data was an unreasonable search and whether the warrant used to identify him was unconstitutional.30 In a 14-1 vote, the court affirmed the lower court’s decision once again.31 This time, the one sentence per curiam opinion provided no substantive guidance to law enforcement or lower courts as to the constitutionality of using these tools.32 Rather, the eight concurrences and one dissent spanning 126 pages reflected a spectrum of answers to both questions. Four concurring judges concluded that no search, and thus no constitutional violation, had occurred,33 three held that the acquisition of the data was an unconstitutional search,34 and two did not take a stance.35 Instead of this tangled web of non-binding opinions, the Fourth Circuit should have provided definitive guidance, holding that the acquisition of data by geofence warrants does constitute a search, as an individual’s reasonable expectation of privacy is infringed when user data is revealed to law enforcement. By alternatively avoiding the constitutional question on procedural grounds, the Fourth Circuit improperly bypassed an opportunity to establish adequate constitutional safeguards for the use of these tools.

A Fourth Amendment search occurs when the government physically intrudes on a constitutionally protected area for the purpose of obtaining information,36 or when the government violates one’s “reasonable expectation of privacy.”37 The “cause of action for [an] illegal search . . . accrues when the wrongful act occurs.”38 Accordingly, a Fourth Amendment violation occurs at the time of an improper search, not at the time of a subsequent arrest or conviction, or any other moment during the criminal justice process.39

Under the reasonable expectation of privacy test, a search occurs when an individual exhibits an actual (subjective) expectation of privacy and that expectation is “one that society is prepared to recognize as ‘reasonable’” (objective).40 Over time, the subjective prong has been minimized; the primary focus is the objective reasonableness inquiry.41 Thus, if a court finds that an objective expectation of privacy is established, an “official intrusion into that private sphere generally . . . requires a warrant supported by probable cause.”42 Otherwise, evidence seized during a search must be suppressed, subject to limited exceptions.43

The Supreme Court has established that individuals generally “have a reasonable expectation of privacy in the whole of their physical movements.”44 In Carpenter v. United States, the Court held that law enforcement’s acquisition of a more primitive form of cellphone tracking technology, cell-site location information (“CSLI”), was an unreasonable search.45 Even though these records were stored and maintained by cell service providers MetroPCS and Sprint, the Court held that retroactively tracking a suspect’s whereabouts violated the defendant’s expectation that the record of his physical movements would be kept private.46 The Court acknowledged that the “digital data at issue . . . [did] not fit neatly under existing precedents,” particularly those under which any privacy right would be destroyed by transmitting data to a third party.47

The use of a geofence warrant constitutes an unreasonable search because the technology shares the very attributes of CSLI searches that concerned the Carpenter Court. The Fifth Circuit, less than a year before Chatrie was reheard, correctly applied Carpenter to the geofence context in United States v. Smith, holding that Google users maintain a reasonable expectation of privacy in their Location History data.48 The court noted that, just like CSLI, Google’s feature leaves a breadcrumb trail behind what would otherwise be one’s private activities, which might include “a visit to ‘the psychiatrist, the plastic surgeon, the abortion clinic, the AIDS treatment center, the strip club, the criminal defense attorney, the by-the-hour-motel, the union meeting, the mosque, synagogue or church, [or] the gay bar.’”49 By acquiring this aggregated data, law enforcement is granted “an intimate window into a person’s life, revealing not only his particular movements, but . . . his ‘familial, political, professional, religious, and sexual associations.’”50

Moreover, since the geofence warrant procedure allows officers to use their discretion when determining which suspects on the Step One and Step Two lists should be investigated further, there is a risk that police may make biased decisions about which users to investigate further.51 The Smith court held that this outcome too closely resembled the unconstitutional “general warrants,” or colonial era warrants that specified only an offense and left “to the discretion of the executing officials the decision as to which persons should be arrested and which places should be searched.”52 Even worse, experts have confirmed that law enforcement could feasibly combine the anonymized data retrieved at Step One or Two with publicly available information to identify users before Step Three.53 The Fifth Circuit reiterated the concern voiced in Carpenter that cell phones “faithfully” follow their owners “into private residences, doctor’s offices, political headquarters, and other potentially revealing locales.”54 Yet, “cell phones and the services they provide are ‘such a pervasive and insistent part of daily life’ that carrying one is indispensable to participation in modern society.”55 These facts persuaded the Fifth Circuit to find that an objective expectation of privacy is held by users in their Location History data.56

In Chatrie, however, four judges voiced their view in concurrence that no expectation of privacy could be held in Chatrie’s data because it revealed only a “two-hour snapshot of [his] public movements.”57 This conclusion is misguided, because even an instantaneous snapshot of one’s location can be incredibly intrusive.58 Additionally, if the length of the period examined determined whether Fourth Amendment rights were infringed, police could ostensibly conduct several short-term searches and aggregate the results to evade Fourth Amendment constraints. This outcome would be patently perverse. As such, and as the Fifth Circuit acknowledged in Smith, the acquisition of this data by law enforcement is sufficiently intrusive to evade expectations of privacy regardless of the duration examined.59

Contrary to the doubts of these same four judges, the fact that users choose to use Google’s location tracking services does not waive their Fourth Amendment protection under the third-party doctrine.60 Under this doctrine, an individual “has no legitimate expectation of privacy in information he voluntarily turns over to third parties,” as illustrated by the two seminal cases United States v. Miller and Smith v. Maryland.61 In the former, the Supreme Court held that a defendant had no legitimate expectation of privacy in his bank records because he had disclosed his affairs with the bank when he voluntarily opened his accounts.62 In the latter, the Court held that a defendant had no legitimate expectation of privacy in the numbers he dialed on his landline telephone because those numbers were revealed to the telephone company by placing the call.63 The Carpenter Court “decline[d] to extend Smith [v. Maryland] and Miller” to cover the “novel circumstances” of CSLI for two reasons: (1) CSLI is conveyed to service providers in a manner that is not meaningfully voluntary, such that users are not sufficiently aware that their data might end up in the hands of law enforcement, and (2) the nature of CSLI is incredibly revealing, making it “qualitatively different” than the business records in Smith v. Maryland and Miller.64 Just like CSLI requests, geofence warrants are not “garden-variety request[s] for information from a third-party witness.”65 Users do not, in any meaningful sense, opt in to revealing their data to the government when using Google applications for everyday purposes, and the information revealed by geofence warrants is just as revealing as CSLI, if not much more so.

As for the consideration of voluntariness, the Fourth Circuit failed to provide a consensus about just how much agency users have when opting in to Google’s feature. Some judges noted that while Location History is not automatically enabled within a Google account, opting in to the feature is “frictionless by design” and difficult to undo, making the assumption that users deliberately choose to participate dubious.66 Other judges found this argument unconvincing because only one-third of Google users use the feature, indicating that two-thirds of users consciously chose not to opt in.67 However, the latter view ignores that no Google users are made adequately aware of just how invasive the feature is, while the prompts to opt in are relentless.68 For instance, Google prompts users to opt in multiple times across every Google app or browser and across various devices.69 The interface encourages users to “[g]et the most from” Google applications through personalized traffic routes and individually-tailored search results, but does not inform users that once enabled, Google will track them across every device logged into their account.70 Google’s privacy warnings are “limited” and “partially hidden,” and do not disclaim that enabling the feature could result in the government’s unfettered access to their every move.71 Users are also not informed that Location History data will continue to be recorded even if all Google apps are deleted from one’s device.72 If a user chooses to “pause” the feature, they are warned that pausing will “limit[] [the] functionality of some Google products over time,” suggesting they cannot use Google to its full efficacy without enabling location tracking.73 Attempting to delete one’s Location History data involves navigating a process that even Google employees described as “difficult enough that people won’t figure it out.”74 As such, the third-party doctrine cannot be applied in good faith to Google’s feature, as a close review reveals not a conscious choice by users to transmit their personal information, but rather users being effectively coerced into participating in location sharing.

As for the nature of the data, Location History data easily falls into the “qualitatively different” category that the Supreme Court distinguished from bank records and phone numbers. In Carpenter, Justice Roberts acknowledged the “world of difference between the limited types of personal information addressed in Smith [v. Maryland] and Miller and the exhaustive chronicle of location information casually collected by wireless carriers today.”75 The Carpenter holding should extend to Location History data because each of the four distinct attributes of CSLI that made it so “qualitatively different” are equally applicable—the data’s comprehensiveness, the intimacy of the information it reveals, its capacity for retrospective tracking, and its ease of access for police.76

Beginning with the first factor, the Location History feature is even more comprehensive than CSLI. Location History records a user’s location over 720 times per day, whereas CSLI logged the user’s location in Carpenter around 101 times per day.77 Further, Location History data is collected regardless of whether the user is actively using their device, while CSLI is only collected when a user makes or receives a call.78 Google’s technology also provides more precise information than CSLI was capable of. Google provides a confidence interval to describe the likelihood that a user was at the recorded location for each data point, and purports to seek an average of 68 percent accuracy.79 Even at this average, the technology is far more precise than CSLI—Location History data is typically accurate up to a three meter radius around a user’s location, while CSLI is estimated to locate users within one-eighth to four square miles.80 Location History can also pinpoint the specific floor of a building a user is on, well beyond the capabilities of CSLI.81

The more comprehensive and precise capabilities of Location History make the feature more intimately invasive than CSLI, as Location History is capable of revealing much more information and collects that information more often. Thus, the intimacy factor that compelled the Court to treat CSLI differently is plainly met in the context of geofence warrants.82

As for the capacity for retrospective tracking, Location History data is again akin to CSLI. Like CSLI, Google’s feature indiscriminately tracks anyone with Location History enabled, regardless of their status as a suspect or their presence in a location normally awarded heightened Fourth Amendment protection, such as one’s home.83 When needed for a criminal investigation, law enforcement can simply apply for a singular warrant to access this vast history of user information with the click of a button. This incentivizes law enforcement to rely on the troves of information already collected by technology companies at the outset of an investigation, rather than first exhausting all leads in a traditional fashion. This shift in the investigatory process has already materialized: In Carpenter, CSLI was used to collect evidence relating to the investigation of an already-identified suspect, whereas the geofence warrant in Chatrie was used to identify the suspect.84 Using this tool earlier in the investigatory process results in more civilians’ rights being infringed upon, since the harm of a Fourth Amendment violation is contemporaneous with the act of an unreasonable search.85 The net effect is that the Fourth Amendment protections imagined by the Framers are diluted.

Finally, the Carpenter Court feared that CSLI searches, which are “easy, cheap, and efficient compared to traditional investigative tools,” eroded the ordinary checks of “limited police resources and community hostility” that typically constrain law enforcement.86 The same concern exists with geofence warrants, but to an even greater degree. Location tracking technologies are “almost twice as cheap as GPS tracking,” which is already “twenty-eight times cheaper than covert pursuit.”87 As such, the ease of police access is just as concerning in the context of geofence warrants as with CSLI.

Each of these distinct characteristics makes Location History data “qualitatively different” from the traditional records analyzed under the third-party doctrine. Courts must acknowledge that the third-party doctrine, a product of doctrinal developments of the 1970s, is simply “ill[-]suited to the digital age,” and instead follow the Supreme Court’s departure from it in the context of digital data.88 On these grounds, the Fourth Circuit should have recognized a legitimate expectation of privacy in Location History data.

Some members of the Fourth Circuit expressed concern that without geofence technology, criminal suspects will go undetected when there is otherwise no forensic evidence available to identify the culprit of a crime, as was the case in Chatrie.89 Nevertheless, “hamstringing the government is the whole point of [the] Constitution.”90 This view also ignores that quite often, geofence warrants do not lead to any perpetrator being identified.91 In these cases, the government has presumably retrieved and retained the highly sensitive data of unsuspecting citizens for no public safety benefit.92 To avoid this exact result, “the forefathers, after consulting the lessons of history, designed [the] Constitution to place obstacles in the way of a too permeating police surveillance.”93 Put plainly, innovations in technology were never intended to “shrink the realm of guaranteed privacy” awarded by the Fourth Amendment.94

Although the Fourth Circuit voiced valid concerns about declaring these tools categorically unconstitutional alongside the Fifth Circuit,95 they failed to explore the plausible middle ground. The constitutional threat posed by geofence warrants could be remedied by requiring review by a magistrate judge at each step of Google’s procedure—as opposed to just at Step One.96 So long as the implementation of such a procedure eliminates the possibility for law enforcement to use their unbounded discretion to narrow down lists of users based on arbitrary attributes, these additional warrant requirements could ameliorate the constitutional concerns of unbounded officer discretion and unchecked searching. This way, geofence warrants could be used for legitimate law enforcement purposes without circumventing the safeguards required by the Constitution.

Under Carpenter, geofence warrants undoubtedly enable Fourth Amendment searches. Courts must remain firm in upholding Fourth Amendment protections to prevent the boundary between law enforcement and technology companies becoming blurred. The Fourth Circuit’s en banc decision in Chatrie offered no relief to Chatrie himself, whose constitutional rights were clearly violated, nor did the decision provide any guidance to lower courts as to how to evaluate the use of these pervasive search tools. Other courts should be wary not to follow in the Fourth Circuit’s footsteps and “perpetuate[] the constitutional fog that will allow unlawful searches of Location History data to continue to evade consequence” on procedural grounds.97 Absent doctrinal clarity on the Fourth Amendment question, courts will continue to struggle with law enforcement’s use of increasingly sophisticated surveillance technology pursuant to little judicial oversight, “an outcome wholly at odds with our constitutional design.”98

* Lily Van Petten is a J.D. Candidate (2026) at New York University School of Law. This Contribution is a commentary on the problem from the 2025 Jerome Prince Memorial Evidence Competition held at Brooklyn Law School. One of the questions presented was whether the government’s use of a geofence warrant to identify a defendant using her location data stored by a third-party technology service provider constituted an unreasonable search under the Fourth Amendment, and if so, whether the geofence warrant satisfied the particularity and probable cause requirements of the Fourth Amendment. This Contribution distills one side of the argument. The views expressed herein do not necessarily represent the author’s views.

1. William Bishop, Mobile Fact Sheet, Pew Rsch. Ctr. (Nov. 20, 2025), https://www.pewresearch.org/internet/fact-sheet/mobile/.

2. See Andrew Laningham, Are Location Sharing Features More Than a Convenient Tool?, The Harris Poll: Briefs (Aug. 2, 2022), https://theharrispoll.com/briefs/location-sharing-features/.

3. See United States v. Chatrie, 107 F.4th 319, 359 (4th Cir. 2024) [“Chatrie II”] (Wynn, J., dissenting), reh’d en banc, 136 F.4th 100 (4th Cir. 2025); see also United States v. Jones, 565 U.S. 400, 417 n.* (2012) (Sotomayor, J., concurring) (“Owners of . . . smartphones do not contemplate that these devices will be used to enable covert surveillance of their movements.“).

4. U.S. Const. amend. IV.

5. United States v. Chatrie, 136 F.4th 100, 115 (4th Cir. 2025) [“Chatrie III”] (en banc) (Wynn, J., concurring) (per curiam).

6. Carroll v. United States, 267 U.S. 132, 149 (1925).

7. See Kyllo v. United States, 533 U.S. 27, 34–35 (2001) (thermal imaging device); Jones, 565 U.S. at 404 (GPS tracker).

8. See Riley v. California, 573 U.S. 373, 386 (2014) (cell phone); Carpenter v. United States, 585 U.S. 296, 310 (2018) (cell-site location information).

9. See Haley Amster & Brett Diehl, Against Geofences, 74 Stan. L. Rev. 385, 389–90 (2022). Google has seen a 1,500% increase in geofence warrant requests from 2017 to 2018, and a 500% increase from 2018 to 2019. See Chatrie II, 107 F.4th at 323–24. In 2020, Google received 11,500 geofence warrant requests, an average of more than thirty geofence warrants per day. See United States v. Smith, 110 F.4th 817, 822 (5th Cir. 2024).

10. Chatrie III, 136 F.4th at 102 n.1 (Diaz, C.J., concurring).

11. See Note, Geofence Warrants and the Fourth Amendment, 134 Harv. L. Rev. 2508, 2512–13 (2021). Approximately 97% of smartphones worldwide use either Google applications, Google’s operating system, or both. Mary D. Fan, Big Data Searches and the Future of Criminal Procedure, 102 Tex. L. Rev. 877, 898 (2024).

12. Chatrie III, 136 F.4th at 144 (Berner, J., concurring).

13. Id. at 102–03 (Diaz, C.J., concurring).

14. Specifically, Chatrie was indicted for two federal crimes: (1) Forced Accompaniment During Armed Credit Union Robbery, in violation of 18 U.S.C. §§ 2113(a), (d), and (e); and (2) Using, Carrying, or Brandishing a Firearm During and in Relation to a Crime of Violence, in violation of 18 U.S.C. § 924(c)(1)(A). See id. at 134 (Richardson, J., concurring).

15. Id. at 157 (Gregory, J., dissenting).

16. See Smith, 110 F.4th at 824.

17. Id.

18. Id.

19. Id. at 824–25.

20. Chatrie III, 136 F.4th at 159 (Gregory, J., dissenting).

21. See Smith, 110 F.4th at 825.

22. Chatrie III, 136 F.4th at 159 (Gregory, J., dissenting).

23. Id.

24. See Smith, 110 F.4th at 825–26.

25. Chatrie III, 136 F.4th at 159 (Gregory, J., dissenting).

26. Id. at 134 (Richardson, J., concurring).

27. United States v. Chatrie, 590 F. Supp. 3d 901, 929 (E.D. Va. 2022) [“Chatrie I”] aff’d, 107 F.4th 319 (4th Cir. 2024), and aff’d en banc per curiam, 136 F.4th 100 (4th Cir. 2025). The district court assumed that a search had occurred since a warrant was obtained in this case and did not conduct a Fourth Amendment standing analysis. Id. at 925; see generally Byrd v. United States, 584 U.S. 395, 411 (2018).

28. Chatrie I, 590 F. Supp. 3d. at 941; see generally United States v. Leon, 468 U.S. 897, 913 (1984).

29. Chatrie II, 107 F.4th at 330.

30. Chatrie III, 136 F.4th at 101–02 (Diaz, C.J., concurring).

31. Id. at 100.

32. Id. at 101.

33. Id. at 109 (Wilkinson, J., concurring); id. at 113–14 (Niemeyer, J., concurring); id. at 115 (King, J., concurring); Chatrie III, 136 F.4th at 130 (Richardson, J., concurring).

34. Id. at 115 (Wynn, J., concurring); id. at 144 (Berner, J., concurring); id. at 157 (Gregory, J., dissenting).

35. Id. at 105–06 (Diaz, C.J., concurring); id. at 141–42 (Heytens, J., concurring).

36. Jones, 565 U.S. at 407.

37. Katz v. United States, 389 U.S. 347, 360 (1967) (Harlan, J., concurring).

38. See Bonelli v. Grand Canyon Univ., 28 F.4th 948, 952 (9th Cir. 2022) (quoting Belanus v. Clark, 796 F.3d 1021, 1026 (9th Cir. 2015)); see also United States v. Karo, 468 U.S. 705, 712 (1984) (explaining that a seizure involves meaningful interference with an individual’s possessory interests, and the violation occurs when such an unreasonable interference occurs).

39. See Bonelli, 28 F.4th at 952.

40. See Katz, 389 U.S. at 361 (Harlan, J., concurring).

41. See Carpenter, 585 U.S. at 346 (Thomas, J., dissenting).

42. Id. at 304 (citing Smith v. Maryland, 442 U. S. 735, 740 (1979)).

43. See Smith, 110 F.4th at 830.

44. Carpenter, 585 U.S. at 310.

45. Id. at 309–10.

46. See id. at 302, 320.

47. See id. at 297.

48. Smith, 110 F.4th at 836 (holding that use of a geofence warrant for Location History data of users within 98,192 square meters around a post office during a three-hour period to identify robbery suspects was a search).

49. Id. at 833 (quoting Jones, 565 U.S. at 415 (Sotomayor, J., concurring)).

50. Id. at 832 (quoting Carpenter, 585 U.S. at 311).

51. See Chatrie III, 136 F.4th at 159 (Gregory, J., dissenting).

52. See Smith, 110 F.4th at 836–37 (quoting Steagald v. United States, 451 U.S. 204, 220 (1981)).

53. See id. at 834 n. 9.

54. Id. at 832 (quoting Carpenter, 585 U.S. at 311).

55. Carpenter, 585 U.S. at 298 (quoting Riley, 573 U.S. at 385).

56. Smith, 110 F.4th at 836.

57. Chatrie III, 136 F.4th at 109 (Wilkinson, J., concurring).

58. See Smith, 110 F.4th at 833.

59. Id.

60. See Chatrie III, 136 F.4th at 105–06 (Wilkinson, J., concurring); id. at 113–14 (Niemeyer, J., concurring); id. at 115 (King, J., concurring); id. at 130 (Richardson, J., concurring).

61. United States v. Miller, 425 U.S. 435, 444–45 (1976); Smith v. Maryland, 442 U.S. at 743–44.

62. Miller, 425 U.S. at 442–43.

63. Smith v. Maryland, 442 U.S. at 744.

64. Carpenter, 585 U.S. at 309, 313–16.

65. Id. at 313.

66. See Chatrie III, 136 F.4th at 128 (Wynn, J., concurring).

67. See id. at 131 (Richardson, J., concurring).

68. See Smith, 110 F.4th at 835.

69. Id. at 823.

70. Chatrie III, 136 F.4th at 152 (Berner, J., concurring); Smith, 110 F.4th at 823.

71. Smith, 110 F.4th at 835–36 (quoting Chatrie II, 107 F.4th at 360 (Wynn, J., dissenting)).

72. See Chatrie III, 136 F.4th at 128 (Wynn, J., concurring).

73. Chatrie I, 590 F. Supp. 3d at 913.

74. Chatrie III, 136 F.4th at 129 (Wynn, J., concurring). Scholars have similarly described that manually deactivating Location History is “difficult and discouraged.” See Amster & Diehl, supra note 9, at 396.

75. Carpenter, 585 U.S. at 314.

76. See id. at 297, 309–13.

77. Chatrie III, 136 F.4th at 151 (Berner, J., concurring).

78. See id. at 145; Carpenter, 585 U.S. at 306.

79. Chatrie II, 107 F.4th at 323.

80. Smith, 110 F.4th at 823; Carpenter, 585 U.S. at 312.

81. Smith, 110 F.4th at 824; Chatrie III, 136 F.4th at 121 (Wynn, J., concurring).

82. See Carpenter, 585 U.S. at 311.

83. See Smith, 110 F.4th at 833–34.

84. See Carpenter, 585 U.S. at 301–02; Chatrie I, 590 F. Supp. 3d at 906.

85. See Bonelli, 28 F.4th at 952.

86. Carpenter, 585 U.S. at 311; Jones, 565 U.S. at 416 (Sotomayor, J., concurring) (quoting Illinois v. Lidster, 540 U.S. 419, 426 (2004)).

87. Chatrie III, 136 F.4th at 125 (Wynn, J., concurring) (quoting Paul Ohm, The Many Revolutions of Carpenter, 32 Harv. J.L. & Tech. 357, 369 (2019)).

88. Jones, 565 U.S. at 417 (Sotomayor, J., concurring).

89. See Chatrie III, 136 F.4th at 110 (Wilkinson, J., concurring). See also Smith, 110 F.4th at 841 (Ho, J., concurring) (“The defendants here engaged in a violent robbery—and likely would have gotten away with it, but for this new technology.”).

90. Smith, 110 F.4th at 841 (Ho, J., concurring).

91. See Note, supra note 11, at 2509–10.

92. See id.

93. United States v. Di Re, 332 U.S. 581, 595 (1948).

94. Kyllo, 533 U.S. at 34. See also Carpenter, 585 U.S. at 320 (quoting Olmstead v. United States, 277 U. S. 438, 473–474 (1928) (“[T]he Court is obligated—as ‘subtler and more far-reaching means of invading privacy have become available to the Government’—to ensure that the ‘progress of science’ does not erode Fourth Amendment protections.”)).

95. Smith, 110 F.4th at 838.

96. See, e.g., Chatrie III, 136 F.4th at 154–55 (Berner, J., concurring).

97. Id. at 156.

98. Id. at 115 (Wynn, J., concurring).