The US supreme court is considering whether sprawling warrants for smartphone location data infringe on Americans’ privacy rights and violate the constitution.
Justices heard opening arguments in Chatrie v United States on Monday that concerned law enforcement’s reliance on so-called “geofence warrants” in difficult cases. The case was originally brought by Okello Chatrie, whose phone location data helped police in Richmond, Virginia, track him down after he robbed a bank at gunpoint and escaped with $195,000 in 2019. Chatrie pleaded guilty to armed robbery and was sentenced to 12 years in prison, but his lawyers argue none of the evidence against him should have been admissible in court.
A lawyer for the US Department of Justice argued that nearly any actions taken in public while in possession of a smartphone afforded no expectation of privacy.
“An individual has no reasonable expectation of privacy in movements that anyone could see, that he has opted to allow a third party to analyze for its own purposes,” the US solicitor general, a high-ranking lawyer for Donald Trump’s administration, has argued in legal filings.
Law enforcement is increasingly demanding that tech companies hand over sensitive phone location data on people at or near a site where a suspected crime occurred – anyone who falls within the radius of a virtual “fence”. These geofence warrants, rather than specifying their targets, instead compel tech companies to hand over data to police or the FBI on every electronic device in a particular place at a given time.
Privacy advocates and some legal experts view geofence searches as a dragnet that sweeps up innocent bystanders. “Just because you have a cell phone, should you be subjected to all sorts of law enforcement investigations because of crimes that may have happened in your vicinity?” said Paul Ohm, a law professor at Georgetown University, who submitted an amicus brief in the case. These warrants can lead to an individual’s phone location data being shared with the police simply because they “were in the wrong place at the wrong time, or even worse – you weren’t, but your phone thought you were”, Ohm added.
Law enforcement officers and prosecutors say these geofence warrants help them solve crimes after reaching dead ends. Justice Brett Kavanaugh expressed concerns about “the practical consequences of not being able to solve murders”.
Chatrie hadturned on an optional Google “location history” feature that documented his location every few minutes. The government noted in its legal filings that “only about one-third of active Google account holders actually opted into the location history service”; Chatrie’s lawyers noted in theirs that this amounted to more than 500 million Google users.
After officers interviewed witnesses at the bank Chatrie robbed and reviewed security footage, they had no leads. In a geofence warrant request, law enforcement requested that Google provide phone location data for a 30-minute period before and after the robbery from all cellphones within 150 meters of the bank, bringing in Chatrie’s phone location data but also information on 19 other accounts. The detective on the case asked Google for more data on all of these people, but the tech company pushed back, and eventually he only requested further information on nine people. Towards the end of the investigative process, that number whittled down to three devices; one was Chatrie’s, and the information included an email address with his name.
The US government has argued in legal filings that Chatrie chose to allow Google to collect and use his phone location data, and that investigators identified him through a warrant – although the plaintiff’s lawyers have argued this warrant was overly broad.
Google, for its part, has changed some of its geofencing policies since Chatrie was arrested. The tech giant has transferred this location data off its servers and onto people’s phones, so that it can’t comply with geofencing warrants in the same way anymore, said Matthew Tokson, a law professor at the University of Utah. But the government is increasingly trying to obtain this information directly from cell phone providers and other companies, he adds. The case still affects “privacy protections for data stored in cloud services and collected by consumer apps”, the Electronic Privacy Information Center noted in a press release.
Privacy advocates warn the implications of this case go far beyond suspected criminals. “If the government doesn’t need to get a warrant or link something to a crime, it could monitor a protest or an abortion clinic or a gun range or a church or an AA meeting or a doctor’s office,” Tokson says. Some justices were worried about the broader privacy implications, too.
If the court rules that a geofence warrant doesn’t constitute a search by law enforcement, “our privacy rights might be completely eviscerated”, Ohm said. “It would lead to a lot of unregulated police activity.” The fourth amendment of the US constitution protects against “unreasonable search and seizure”. Both Ohm and Tokson got the sense from the judges’ remarks on Monday that at least some justices seemed likely to find these geofence warrants counted as a search, which should bring some relief to privacy advocates.
Justice Sonia Sotomayor suggested on Monday that she wasn’t convinced by the government’s argument that short-term location information doesn’t reveal much about an individual’s patterns of life. She explained how people take their phones everywhere, from the bathroom, to a cannabis shop to a brothel. “It really doesn’t matter … whether it’s a minute that you’re searching for or six weeks, it’s not the time that’s an issue – it’s whether or not private information in which you have a reasonable expectation of privacy will be sought,” she said.
