Rule that cell phone location info generally requires probable cause warrant

In a decision that could have wide implications for privacy in the digital age, the Supreme Court, in a 5-4 decision, has ruled that law enforcement must get a probable cause warrant, not simply a court order under the Stored Communications Act, to access certain communications stored by communications service providers, specifically cell site location information.

Law enforcement uses that data to try and match up movements and whereabouts with crimes

In his majority opinion, Chief Justice John Roberts said that "a majority of the Court has already recognized that individuals have a reasonable expectation of privacy in the whole of their physical movements. Allowing government access to cell-site records—which “hold for many Americans the ‘privacies of life,’ contravenes that expectation."

He wrote that the decision was narrow and did not threaten "conventional surveillance techniques," or preclude such searches under special circumstances, but said: "We decline to grant the state unrestricted access to a wireless carrier’s database of physical location information." 

Related: Cloud Act Promotes Surveillance Data Access Framework 

The court was overturning a lower court ruling that the government's acquisitions of such records under a court order, but not a warrant, was not a violation of Fourth Amendment property and privacy protections-against unreasonable search and seizure--because there was was no reasonable expectation of privacy since the location information had been shared with wireless carriers. 

The court held that the government's acquisition of cell site records was a Fourth Amendment search and that, while digital data does not fit neatly into existing precedent, the third-party doctrine that reduces the expectation of privacy when information is shared with a third party cannot be "mechanically applied" since cell phone location information is not "truly shared" but is part and parcel of using a service that is "ervasive and insistent in modern society." 

The majority voting to reverse the lower court comprised Roberts and the more liberal Justices Ruth Bader Ginsburg, Sonya Sotomayor, Elena Kagan and Steven Breyer. 

"The desire to make a statement about privacy in the digital age does not justify the consequences that today’s decision is likely to produce," wrote Justice Samuel Alito in his dissent. "Legislation is much preferable to the development of an entirely new body of Fourth Amendment caselaw for many reasons, including the enormous complexity of the subject, the need to respond to rapidly changing technology, and the Fourth Amendment’s limited scope."   

Congress has been wrestling for years with how the government should be able to obtain data, in what instances, and with what legal protections, but has yet to come up with a comprehensive legislative solution. 

“The Supreme Court’s decision today will have far-reaching impacts because it extends Constitutional protections to cell-site location information and not just to the actual content or words and sounds of a cellphone call or text message," said Syracuse University law professor William Snyder. “The government now needs a warrant issued by a judge in order to obtain long-term, detailed records of the location of a cell phone.  The ruling also is significant because the Court reasons that Constitutional protections against unreasonable searches and seizures must change as technology advances – surely a sign that more change will come."

“We are encouraged by the Court’s decision to afford location information stored with mobile service providers the level of Fourth Amendment protection that users expect for all their digitally-maintained data," said Computer & Communications Industry Association president & CEO Ed Black. "This decision will provide users with the confidence that the sensitive location data they share with innovative digital devices and services will only be disclosed to law enforcement with a warrant based on probable cause." 

“Storage of location data with service providers is an increasingly necessary part of digital life, and will only become more essential as more connected devices come online. While the Court’s decision is narrow, its reasoning could have significant impact on the future application of the Fourth Amendment’s protections to digital data.”