When police cannot identify a suspect, they increasingly turn to technology companies rather than witnesses. The Supreme Court confronted one of the most aggressive versions of this practice in Chatrie v. United States (Chatrie), No. 25-112, decided June 29, 2026. The case involved the “geofence warrant,” which compels a company like Google to identify every cell phone that passed through a given area at a given time. Writing for the majority, Justice Kagan held that police conduct a Fourth Amendment search when they obtain a person’s detailed location data from Google (known as “Location History”) — even for a window as short as two hours, and even though the data sits on a third party’s servers. The ruling is a significant win for digital privacy, reaffirming that handing information to a tech company for one purpose does not mean handing it to the government for another. CCIA joined with the Software & Information Industry Association to file an amicus brief supporting this decision.
Background of the Case
Chatrie arose from a 2019 credit union robbery in Midlothian, Virginia. Unable to identify a suspect, police obtained a warrant directing Google to run a three-step geofence process: first producing anonymized location data for every phone within 150 meters of the bank, then expanding the search for a narrowed list of devices, and finally unmasking the names behind the remaining accounts. That process identified Okello Chatrie, who was later convicted of the robbery. The district court found the warrant unconstitutional but admitted the evidence anyway under the good-faith exception, and a fractured Fourth Circuit affirmed, dividing evenly on whether a search had even occurred. The Supreme Court granted review solely on that threshold question, and Justice Kagan’s majority opinion held that a search did occur, extending the logic of Carpenter v. United States, 585 U.S. 296 (2018) to this newer, more precise form of tracking.
The Decision
Justice Kagan’s opinion rests solidly on Carpenter, noting that “Everything Carpenter relied on to find that law enforcement officers conducted a Fourth Amendment search when they accessed wireless carriers’ cell-site location information (CSLI) records applies as well or better to the police’s accessing of Google’s Location History data[,]” Chatrie, No. 25-122, slip op. at 18, and she identified three key parallels. First was the precision of the data at issue: cell-site records placed a phone within a sector of one-eighth to four square miles and logged a location roughly 101 times a day, while Location History pinpoints a phone within about twenty meters, logs a position every two minutes — some 720 times a day — and can even identify which floor of a building a phone occupies. Id. at 16-17. Second was the retrospective reach of the data: because Google maintains a running record of a user’s whereabouts, police can reconstruct months of a person’s movements after the fact with a single request, achieving what the Court called “tireless and absolute surveillance” without ever deciding in advance whom to follow. Id. at 17-18. Third, and most distinctive, Location History belongs to the user in a way cell-site records never did: most subscribers do not even know cell-site records exist, but Google users actively consult, edit, and rely on Location History as a personal travel diary, making it more akin to emails, photographs, or calendar entries than to a business record a phone company generates incidentally. Id. at 18.
The government offered two main arguments against extending privacy protection to this data, and Justice Kagan rejected each in turn. First, the government argued that two hours of data was too brief a window to implicate the Fourth Amendment at all. Kagan responded that even short-term monitoring can reveal deeply private facts — a visit to a psychiatrist, an abortion clinic, or a place of worship — and that Fourth Amendment protection has never depended on the quantity of information the government manages to gather; a search is a search regardless of how much it turns up. Id. at 20-23.
Second, the government invoked the third-party doctrine, insisting that Chatrie forfeited any privacy interest the moment he chose to enable Location History on his own phone. The third-party doctrine arises from two cases – United States v. Miller, 425 U.S. 435 (1976), and Smith v. Maryland, 442 U.S. 735 (1979) – which respectively found that the Fourth Amendment did not require law enforcement to obtain warrants to access suspects’ bank records and phone numbers dialed because the information had been given voluntarily to third parties. By analogy, the government argued that Chatrie lacked a reasonable expectation of privacy in Location History he voluntarily and affirmatively provided to Google.
Justice Kagan responded that the third-party doctrine was inapplicable to this case. As the Court held in Carpenter, cell phones were a “pervasive and insistent part of daily life” and thus the sharing of data could not be voluntary in any meaningful sense. Chatrie, No. 25-112, slip op. At 25 (quoting Carpenter, 585 U.S. at 315). The Court also found that the information sharing was not voluntary because Google repeatedly prompted users to turn on location sharing, even cautioning that the phone would not work correctly without it. Moreover, Google did not disclose to users how frequently and with what precision location data would be provided to Google, nor that such detailed information could be provided to law enforcement – without such information, the sharing decision could not be voluntarily made. Id. at 26-27. And, though the government pointed to the fact that only a third of Google users opted for location sharing as evidence that the choice was voluntary, Justice Kagan rejected this argument as leading to unworkable questions of what adoption rates made disclosures involuntary. Id. at 26-27.
Critically, Justice Kagan concluded that the government’s argument faced a “deeper problem;” it misapprehended “the very nature of modern cell-phone use” in which “[p]retty much everything a person does on a smartphone requires some kind of opt-in . . . [a]nd each activity, like using Location History, results in sharing information with a third-party tech company.” Id. at 28. As she stated, “The point of carrying smartphones is to use what is on them–to use the apps and services they provide. That is what has become a pervasive and insistent–even indispensable–part of daily life.” Id. (emphasis in original, cleaned up). Given that reality, Justice Kagan held that “[a] cell-phone user is not to be viewed as sharing private information with third parties–which can then be freely passed on to the government–just by doing the ordinary things cell-phone users do.” Id. at 29.
Justice Jackson, joined by Justice Sotomayor, concurred separately to argue that the warrant’s later stages plainly lacked the particularity the Fourth Amendment demands. Justice Gorsuch concurred only in the judgment, urging the Court to abandon the Katz “reasonable expectation of privacy” framework altogether in favor of treating Location History as Chatrie’s personal “effect.” Justice Alito, joined in part by Justices Thomas and Barrett, dissented, arguing both that the case should never have been decided on the merits and that, under the traditional third-party doctrine, voluntarily generated location data deserves no Fourth Amendment protection. Justice Barrett dissented separately, agreeing with Alito’s conclusion even while accepting Carpenter itself as settled law.
Analysis
What makes this decision such a significant step forward for privacy is how directly it confronts, and rejects, the government’s central argument: that because Chatrie chose to enable Location History, he voluntarily surrendered any privacy interest in it to Google, and therefore to the police as well. The Court refused to let that logic stand. Justice Kagan’s opinion recognized that modern life simply does not permit people to use a smartphone without constantly generating data through some third party’s servers. Sending an email, saving a photo, or checking a map – actions the Court clearly sees as analogous, see Chatrie, No. 25-112, slip op. at 18 – all require the same kind of “affirmative act” the government tried to treat as disqualifying. Treating every such act as a forfeiture of privacy would mean, in practice, that the Fourth Amendment almost never protects information accessed through a phone. By insisting that Location History is “not truly shared” in any meaningful sense, id. at 25, the Court preserved the idea that a person can entrust information to a company for a specific purpose — better maps, more useful reminders — without thereby exposing his entire life to government inspection.
The opinion is also notable for what it refused to allow the government to use as a loophole: duration. The government argued that a mere two hours of location data was too brief to trigger constitutional protection, in contrast to the week of records at issue in Carpenter. Kagan’s opinion firmly closed that door, explaining that the Fourth Amendment does not switch on only once a search “goes too far,” id. at 20, and that a rule based on time windows would just invite the government to request data in short bursts while still assembling, over time, the same comprehensive picture of a person’s life that concerned the Court in Carpenter. Just as importantly, the Court treated Location History as more deserving of protection than the cell-site records in Carpenter — not less — because users actually consult, edit, and rely on it as a personal record, much like an email inbox or a photo album. That framing matters enormously going forward: it signals that courts should look not just at how a company handles data internally, but at how ordinary people actually understand and use the information they generate, when deciding whether the government may demand it without judicial oversight.
Conclusion
Taken together, the decision narrows the third-party doctrine’s reach at a time when nearly every meaningful record of a person’s life is held not in a drawer at home but on a corporate server somewhere. By declining to treat “voluntary” use of common phone features as a waiver of privacy or carve out duration-based exceptions that police could easily manipulate, the Court has made clear that digital-age data deserves the same protection as the physical “papers and effects” the Fourth Amendment was written to shield. Whether the geofence warrant in this particular case was adequately particular and supported by probable cause remains for the Fourth Circuit to decide on remand, but the underlying constitutional floor is now considerably higher than before.
