Supreme Court puts limits on cellphone location data searches

WASHINGTON — When police officers sweep up location data from cellphone users near crime scenes, they must comply with the Fourth Amendment, the Supreme Court ruled Monday in a modest victory for privacy rights in the digital age.

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Such so-called geofence searches have become a popular tool for law enforcement, but critics say they put at risk the personal data of everyday Americans and violate the Fourth Amendment, which prohibits unreasonable searches and seizure.

“An individual has a reasonable expectation of privacy in records about his cellphone’s location, 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,” Justice Elena Kagan wrote for five justices in the 6-3 decision.

But her opinion went no further, and it returned the case to a lower court to decide whether the search at issue in the case, which took place after a Richmond bank robbery, had violated the Constitution. “It is therefore now up to the court of appeals,” she wrote, “to decide whether, at each step of the search process, the warrant satisfied the Fourth Amendment’s requirements of particularity and probable cause.”

An ideologically mixed group of justices made up the majority, with Chief Justice John Roberts and Justices Sonia Sotomayor, Brett Kavanaugh, and Ketanji Brown Jackson joining Kagan. Justice Neil Gorsuch agreed with the majority’s bottom line but not its reasoning.

In dissent, Justice Samuel Alito wrote that the majority had destabilized the law in ways that “will send seismic waves through our Fourth Amendment doctrine,” adding: “I cannot support this irresponsible escapade.”

Justices Clarence Thomas and Amy Coney Barrett joined parts of Alito’s dissent.

In her majority opinion, Kagan grappled with how to apply the Fourth Amendment’s traditional protections against unreasonable searches to rapidly changing technology that has made it easier for the police to scoop up vast amounts of data to assemble a detailed look at a person’s movements and activities.

It had been eight years since the court last took up a major case involving the expectations of privacy of the millions of people carrying cellphones in the digital age. In that 2018 case, the court ruled that the government generally needs a warrant to collect location data drawn from cell towers about customers of cellphone companies.

The court has also limited the government’s ability to use GPS devices to track suspects’ movements, and it has required that law enforcement get a warrant to search individual cellphones.

Monday’s decision in Chatrie v. United States involved a broader kind of search. It involved Okello T. Chatrie, who was convicted in the 2019 armed robbery of a Virginia bank. Police used a geofence search to capture location data from all the cellphones in the vicinity of the bank for 30 minutes before and after the robbery, and identified Chatrie as a suspect. He challenged the search after his conviction.

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In Chatrie’s case, the government did obtain a warrant, but one that his lawyers said sought an overly broad set of data and violated the Fourth Amendment.

The Justice Department told the justices that a warrant had not been needed at all to review anonymous location data.

What the ruling will ultimately mean for Chatrie is unclear, but Alito predicted that “not one iota of the majority opinion will affect the outcome.”

Millions of Americans use a Google service known as “location history,” which gathers data roughly every two minutes about where its users travel and when. That creates a powerful set of information law enforcement can use to try to solve crime.

Unlike traditional warrants, which target an identified suspect based on probable cause that he or she has committed a crime, geofence warrants operate in reverse. Law enforcement draws a virtual fence, or boundary, around a geographic area where a crime has been committed and asks technology companies for data on every user whose device happened to be in the area during a particular time frame.

Chatrie’s lawyer argued to the court that a person’s location history, which can be reviewed, edited and deleted, is akin to private property because the data is stored in a password-protected account. Even if Chatrie had agreed to share the information with Google, his lawyer said he had not agreed to share it with the government.

The solicitor general’s office countered that Chatrie had voluntarily shared his location data with Google. Similar to a person’s bank or phone records, which are held by a business, the government argued that there is no expectation of privacy for information that someone chooses to share with a third party.

Google says it stopped responding to geofence warrants last year, because the company no longer stores such data and instead keeps location data on each user’s device. But law enforcement has made similar geofence requests of other tech companies, including Apple, Lyft, Snapchat, Uber, Microsoft, and Yahoo, meaning the Fourth Amendment questions before the justices have remained relevant.

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This article originally appeared in The New York Times.