A federal judge has ruled that cops need to get a warrant if they want to access a person's past cellphone location data, in what digital rights activists call a big win for privacy.
Currently, police can access your cellphone records, including information about your past locations, without a court order. On Monday, Judge Susan Illston, of the Northern District of California, ruled against that doctrine, saying that people have a reasonable expectation of privacy in their historical location data collected by cellphone providers.
That means historical location data collected from cell towers is protected by the 4th Amendment, which protects against unreasonable searches and seizures.
Cellphones are "ubiquitous" and "an indispensable gizmo" for many people, and they transmit "enormous amounts of data," including details people's location, Judge Illston wrote in her opinion, which was published online on Thursday. That's why, she argued, this data deserves special protection.
While Illston is not the first judge to hold this opinion, and the ruling doesn't bind any other courts, digital rights activists applauded the decision because, they argued, it's yet another step towards more privacy protections in the digital age. Traditionally, the US government and law enforcement has argued that personal data stored by third parties, such as cellphone providers, is not protected by the 4th Amendment.
"It's certainly a win for privacy," Nate Wessler, a staff attorney with the ACLU's Speech, Privacy, and Technology Project, told Motherboard.
Kevin Bankston, who has litigated many privacy cases in the past and is now the policy director for the New America Foundation, said that while this decision is not "out of the blue or unprecedented," it is "a major victory in a decade-long fight."
"It's just another building block in the fight for warrants for location tracking and for government access to stored location data," he told Motherboard.
This opinion seems to confirm a trend toward more privacy protections when it comes to cellphone location data. In June of last year, the Eleventh Circuit held that historical cell -site data is protected by the 4th Amendment, disagreeing with a 2013 decision from the Fifth Circuit.
The full opinion is embedded below.