Supreme Court ruling guts government’s use of geofence warrants - Ars Technica
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The Fourth Amendment protects a user’s “location history,” the Supreme Court ruled Monday.
The same logic already applied to a cellphone’s tracking, and the high court found “no good reason exists to reach a different result for Location History” collected by third parties like Google.
Split 6-3, the majority agreed that the government needs a warrant and must show reasonable cause to turn a phone’s location-tracking services into a government surveillance tool.
The decision came in a case where cops used so-called geofence warrants to track down an armed bank robber from a list of all phones logged in the area. Applying a three-part process, cops worked with Google to narrow down the list of suspects and eventually arrested Okello Chatrie, who had opted in to share his location with Google every few minutes. Chatrie was sentenced to 12 years in prison but challenged the geofence warrant as an unconstitutional search.
The US tried and failed to argue that no search was conducted under the Fourth Amendment, partly because they only searched a little bit of Chatrie’s location data, which the government considered too small to warrant privacy protections.
They also claimed that Chatrie was aware that voluntarily sharing his location with Google could mean that law enforcement might get access to the data. And along similar lines, the government argued that Chatrie’s data simply showed his movements in public, where he supposedly had no reasonable expectation of privacy.
However, Justice Elena Kagan, penning the majority opinion, said it didn’t matter how much data the government obtained. It was still a search under the Fourth Amendment because people carrying cellphones today commonly opt in to location-tracking, so that their apps work.
“Google repeatedly prompts users to turn on the service, often warning that devices will not ‘work correctly’ otherwise, while not disclosing in that prompt how frequently users’ location information would be recorded, how precise it would be, or how it might be given to the government,” the majority agreed.
Much like carrying a cellphone is part of modern life, so is allowing a third party to track your movements, and that doesn’t diminish a person’s right to privacy, the majority ruled. Justice Sonia Sotomayor noted that “even short-term monitoring” of where a person has been can reveal “a wealth of detail about [his] familial, political, professional, religious, and sexual associations”—particularly if he’s seen visiting a sensitive location, like a clinic, an attorney’s office, or a strip club.
“An individual has a reasonable expectation of privacy in records about his cell phone’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,” Kagan wrote.
Privacy advocates cheered the ruling, even though it “stopped short of striking down these warrants as inherently unconstitutional,” the surveillance litigation director of the Electronic Frontier Foundation, Andrew Crocker, said in a statement provided to Ars.
“We applaud the Court’s decision,” Crocker 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.”
Tech companies also moved to support the ruling. Matt Schruers is CEO of a trade association that counts Google and Apple among members, the Computer & Communications Industry Association. In a statement, he celebrated the ruling for clarifying that “the Fourth Amendment fully protects people’s rights to privacy from government intrusion.”
“We are encouraged to see the Court recognize that privacy interests persist regardless of the technology involved, and that law enforcement must seek judicial authorization to obtain Americans’ geolocation information,” Schruers said.
Dissent argued for app-by-app basis
Most justices agreed that a common standard that the Fourth Amendment applies to all location history was necessary to avoid future court battles that could potentially draw different lines between different apps and phone features.
Kagan suggested that in arguing for an app-by-app basis, the government was trying to “disconnect the activities people do on their cell phones from the mere act of carrying a turned-on cell phone,” with...