The US Supreme Court has ruled that constitutional privacy protections extend to cell phone location information, a decision with broad implications for anyone who carries a smartphone. The ruling places limits on how easily authorities can rely on the trails of location data that modern devices constantly generate.
The case arose from the prosecution of a bank robber whose identity was discovered through a geofence warrant, a tool that lets investigators identify the devices, and by extension the people, present in a given area at a given time. By taking up that case, the justices confronted how far law enforcement can reach into digital location records.
The court divided 6-3, with Justice Elena Kagan writing for the majority. The split underscored that the question of digital privacy does not fall along simple lines, and that the justices wrestled with how established constitutional principles should apply to data collected by everyday technology.
At the heart of Kagan's reasoning was the idea that people do not forfeit their expectations of privacy even when they opt into a service such as Google's location history. In other words, agreeing to let a device track location for convenience does not amount to surrendering all constitutional protection over that information.
Kagan framed the decision as the court's latest effort to apply a constitutional provision ratified in 1791 to technology the nation's founders could not have envisioned. That tension, between centuries-old text and modern surveillance capabilities, has become a recurring theme as the justices weigh how privacy rights translate to the digital age.
The ruling came as part of a series of decisions handed down as the Supreme Court moves to close out its term, alongside other closely watched cases on election procedures and presidential power. Additional major rulings, including on birthright citizenship and transgender athletes, were still expected, but the location-data decision stands out as a significant marker for digital privacy.