Supreme Court Limits Geofence Warrants in a Landmark Digital-Privacy Ruling

Supreme Court Limits Geofence Warrants in a Landmark Digital-Privacy Ruling

In a decision that redraws the constitutional map of the smartphone era, the U.S. Supreme Court on June 29 ruled that when police compel a tech company to sweep up cell-phone location data from everyone near a crime scene, they are conducting a search under the Fourth Amendment — one that demands the same probable cause as any other. By a vote of 6-3 in Chatrie v. United States, the justices sharply narrowed the reach of the "geofence warrant," a dragnet tool that has become a fixture of American policing over the past decade.

Writing for the majority, Justice Elena Kagan grounded the holding in a simple proposition about modern life. "An individual has a reasonable expectation of privacy in records about his cell phone's location," she wrote, "and police intrude on that constitutionally protected interest when they demand the information — even though for only a limited time, and from a third-party tech company." The ruling does not ban geofence warrants outright. Instead, it strips away the theory that had let investigators treat mass location dumps as something less than a search, forcing them to justify each request against the Fourth Amendment's demand for particularity.

The case that got here

The dispute traces back to a 2019 armed robbery at a federal credit union outside Richmond, Virginia. A man handed a teller a note and left with nearly $200,000. Investigators had no leads — until they served Google with a geofence warrant, instructing the company to identify every device it had logged within a 150-meter radius of the bank during a window around the robbery, an area spanning several football fields and encompassing homes, businesses, and a church.

Google answered in tranches: first a list of 19 anonymized accounts, then narrowed data on nine, and finally the names and details of three — one belonging to Okello Chatrie. That data led police to two residences, where they recovered roughly $100,000 in cash, a gun, and the demand notes. Chatrie pleaded guilty but preserved his right to challenge the search. A federal district judge had already found the warrant lacked the probable cause the Constitution requires, yet allowed the evidence in under the "good faith" exception. A divided en banc Fourth Circuit affirmed, reasoning that Chatrie could not expect two hours of location data he had voluntarily let Google collect to stay private.

The Supreme Court rejected that logic.

Building on Carpenter

Chatrie is the Court's first major digital-surveillance ruling since Carpenter v. United States in 2018, which held that police need a warrant to obtain historical cell-site location records. Carpenter had carved a hole in the "third-party doctrine" — the longstanding rule that information voluntarily handed to a company loses Fourth Amendment protection. Chatrie widens that hole.

The government argued that Chatrie forfeited any privacy interest by opting into Google's Location History. Kagan was unpersuaded, noting the data "is the automatic price of conventional cell-phone usage" and far more revealing than the ordinary business records the third-party doctrine was built for. If anything, the majority observed, Location History was a sharper instrument than the cell-site data in Carpenter — pinning Chatrie to within roughly 20 meters and logging his position about seven times as often. Even short-term tracking, the Court held, can expose "a wealth of detail about a person's familial, political, professional, religious, and sexual associations."

The Court went further, signaling that the records our apps generate — "emails, documents, photographs, [and] calendars" as well as location — are the user's own and shielded from "the inquisitive eyes of the government," even when we click "agree." In a concurrence, Justice Neil Gorsuch called location data a user's "personal property," no different from the "effects" the Fourth Amendment protects by name.

Justice Samuel Alito, joined in part by Justices Clarence Thomas and Amy Coney Barrett, dissented bitterly, warning that the majority's reasoning "will send seismic waves through our Fourth Amendment doctrine" while doing nothing to actually help Chatrie, whose case now returns to the lower courts.

Why it matters in the AI age

The stakes reach well beyond one robbery. Geofence requests exploded over the past decade, with Google — the primary recipient — reporting thousands per year at their peak. The company preempted much of the fight in 2023 by changing how it stores Location History; since July 2025, mass geofence searches of Google users have effectively become impossible. But the underlying architecture of location surveillance remains.

That architecture is increasingly powered by artificial intelligence. Location traces are the raw feedstock for pattern-of-life analytics, predictive policing, and the data-broker industry that aggregates app signals and sells them to police. AI turns scattered pings into inferences — who lives with whom, who attends which protest, who visits which clinic. By anchoring location data firmly within the Fourth Amendment, Chatrie raises the constitutional cost of feeding that machinery.

Civil-liberties groups declared victory. EFF, which joined the ACLU and Georgetown Law's Center on Privacy & Technology in an amicus brief, called geofence warrants "the digital equivalent of police going person to person, home to home, without suspicion." Andrew Crocker, EFF's Surveillance Litigation Director, said the Court "reaffirmed that you have an expectation of privacy in location data that reveals your movements in the physical world, and that even short-term surveillance of these movements is a search subject to the Fourth Amendment."

What to watch

The decision leaves loose ends. The justices declined to say whether Chatrie's specific warrant was "reasonable" or whether the good-faith exception salvages the evidence — questions now back before the Fourth Circuit. And Chatrie addresses Google's geofence pipeline, not the parallel channels that remain wide open: cell-tower dumps, license-plate readers, and data brokers that route app-derived location to police without any warrant at all.

The larger test is whether courts read Chatrie narrowly, as a ruling about one dragnet technique, or broadly, as the Court's clearest statement yet that the digital exhaust of everyday life belongs to the person who generates it. In an era when smartphones and AI make near-total surveillance technically trivial, that is the line the next decade of Fourth Amendment law will be drawn along.