Supreme Court Draws Line on Police Sweeps of Phone Location Data

The Supreme Court handed privacy advocates a significant win Monday. In a 6-3 decision, the justices ruled that police use of geofence warrants to collect smartphone location records from scores of innocent bystanders counts as a search under the Fourth Amendment.

Justice Elena Kagan wrote for the majority in Chatrie v. United States. The opinion builds directly on the court’s 2018 Carpenter v. United States precedent. There, prolonged cell-site location information tracking required a warrant. Now even shorter bursts of data demand similar safeguards.

But. The ruling stops short of declaring all such warrants unconstitutional. It sends the case back to lower courts to weigh whether the specific warrant used against Okello Chatrie was reasonable. Still, the core holding lands hard. Location data reveals too much. Police cannot vacuum it up without particularized suspicion.

Chatrie robbed a bank in the Richmond, Virginia suburbs in May 2019. He made off with $195,000. The case went cold for two months. Investigators then secured a geofence warrant from Google. It compelled the company to search location history from any device that had been inside or near the bank in the hour surrounding the crime.

Google identified three users. One was Chatrie. Further digging turned up a matching pistol and cash at his home. He confessed. Convicted of armed robbery.

His lawyers fought the evidence. They argued the warrant swept up data from thousands without cause. It turned bystanders into suspects. The digital equivalent of cops knocking on every door in a neighborhood. Without reason to believe any particular resident committed the crime.

A federal district judge in Virginia agreed the warrant violated the Fourth Amendment. Yet she let the evidence stand under the good-faith exception. Police had relied on it. The Fourth Circuit, sitting en banc, split badly but ultimately affirmed on that narrow ground.

The Supreme Court took the case to settle whether accessing this data triggers constitutional protections at all. It does. “Even short-term surveillance of these movements is a search subject to the Fourth Amendment,” Kagan explained, according to the Electronic Frontier Foundation.

The opinion stresses that location records expose “a wealth of detail about a person’s familial, political, professional, religious, and sexual associations.” Private matters. The sort the Fourth Amendment exists to shield from government eyes.

And the data comes from apps on our phones. Not just the carrier signals that ping cell towers. Users generate it when they open maps, order food, check the weather. They reasonably view those records as their own. The court rejected the government’s third-party doctrine argument here. Sharing with tech firms doesn’t forfeit privacy. Not when the alternative is to forgo carrying a smartphone. Which few can do in modern life.

Justice Neil Gorsuch concurred in the judgment. He went further. Location data counts as the user’s “personal property,” no different from other “effects” the Fourth Amendment explicitly protects. His separate writing, noted in coverage from SCOTUSblog, could open new avenues for challenging data collection practices.

Justice Ketanji Brown Jackson joined a concurrence with Justice Sonia Sotomayor. They reinforced the privacy stakes. Justice Samuel Alito dissented, joined in part by Justices Clarence Thomas and Amy Coney Barrett. He worried the decision would hamper legitimate police work. Barrett wrote a separate dissent.

The practical effects could prove wide. Geofence warrants had become a favorite tool. They let investigators start with a crime scene and work backward to identify potential suspects. No name required upfront. Just a geographic perimeter and time window. Google often returned anonymized data first, then identified users only if police showed more cause.

Yet critics saw abuse. One warrant might pull records from hundreds or thousands of devices. In dense urban areas or events like protests, the numbers balloon. Innocent people land in police databases. Their movements mapped without ever being suspected of wrongdoing.

Google itself moved to limit the practice. In 2023 the company announced changes to location history storage. By mid-2025, mass geofence responses became impossible for its users. The shift came too late for Chatrie’s 2019 case. But it signaled industry recognition of the privacy risks.

Other data sources remain. Brokers sell aggregated location pings harvested from countless apps. Police buy them or seek cell-tower dumps that capture everyone nearby. The Electronic Frontier Foundation has documented these practices extensively. The new ruling supplies ammunition to challenge them.

Andrew Crocker and Jennifer Lynch, who authored the EFF analysis, called it a victory. “The Court also recognized the records generated by the apps on a user’s phone—records we necessarily share with third-party tech company—are a user’s ‘own’ and require Fourth Amendment protection.” Their piece links the decision to broader app data. Emails, photos, calendars. All get stronger shields.

Recent reporting echoes the momentum. NPR detailed how the technique lets police “tap into giant tech-firm databases to see who was near the scene of a crime.” Kagan’s opinion, per the outlet, guards against a “virtual panopticon.” Constant potential surveillance that chills free movement and association.

NBC News highlighted the remand. Lower courts must now test the warrant’s reasonableness. Chatrie’s team will argue it lacked particularity. It didn’t name him or tie him to the crime before demanding the data haul. That step-by-step narrowing process Google once offered may not save future warrants.

Privacy groups had urged the court to go all the way. The Brennan Center for Justice, in its brief, warned geofence tools enable “reverse search” warrants. They chill First Amendment activity. Imagine authorities drawing a digital fence around a mosque, a political rally, a doctor’s office. The data reveals who showed up.

The ruling arrives at a moment of heightened scrutiny over commercial surveillance. Data brokers feed law enforcement with precise movement histories. Cars, fitness trackers, even in-app advertising beacons contribute. The court didn’t address those streams directly. Yet its logic—that people retain privacy expectations in digital trails—invites future cases.

Lower courts had split before the Supreme Court stepped in. The Fifth Circuit called geofence warrants categorically unconstitutional. The Fourth Circuit punted on good faith. Now a uniform principle applies. Location data from phones gets Fourth Amendment treatment. Short or long term.

Investigators won’t lose every tool. Traditional warrants remain available when they target specific suspects. Probable cause tied to an individual device or account. The dragnet approach faces higher hurdles.

So the balance shifts. Police must show cause before they cast wide nets. Citizens gain breathing room from perpetual tracking. The decision doesn’t ban geofencing outright. It insists on constitutional guardrails.

That nuance matters for tech companies too. They face fewer blanket demands. Users may feel more secure keeping location services on. The point of smartphones, after all, is the apps. The court recognized as much. “The point of carrying smartphones is to use what is on them,” the opinion states, as quoted by EFF.

Reactions poured in fast on social media. Many hailed a privacy triumph. Others fretted over unsolved crimes slipping away. The debate will continue in legislatures and lower courtrooms.

For now, the Supreme Court has spoken clearly. The Constitution follows us into the digital world. Our phones don’t surrender their secrets so easily. Law enforcement must respect the line. Even when technology makes crossing it tempting.