On Wednesday a federal appeals court held that the government generally needs a warrant in order to inspect one’s past cellphone location data. The three-judge panel from the U.S. Court of Appeals for the Fourth Circuit found that cellphone users have “an objectively reasonable expectation of privacy” in cell site location information (CSLI). (United States v. Graham, No. 12-4659 (4th Cir. Aug. 5, 2015).)
Where Were We?
In the case that led to the ruling, a federal jury convicted two men of charges related to several armed robberies in the Baltimore area. Officers nabbed the suspects shortly after the last robbery, then seized various items, among them their cellphones.
The government gathered court orders granting access to the phones’ CSLI. Pursuant to those orders, the phone’s service provider (Sprint/Nextel) handed over seven months’ worth of CSLI records. Prosecutors used those records to prove the defendants’ whereabouts at various times surrounding the robberies.
In the course of its opinion, the Fourth Circuit panel explained how CSLI works: A traditional cellphone communicates with cell sites whenever it sends or receives a call or text, while a smartphone might communicate with them more often due to functions like email. The phone typically connects to the nearest cell site because that site offers the strongest signal. Records of the sites to which a phone has connected therefore show the approximate whereabouts of the device—and its user—at precise moments in time. (Listeners to Serial will forgive the recap.)
Searching for a Standard
The government secured the location records through the Stored Communications Act (SCA). The SCA requires that the government get either a warrant or court order for a service provider’s subscriber account records.
Warrants demand probable cause, but SCA court orders can rest on what’s essentially reasonable suspicion, a lower standard. (The SCA allows for orders based on “reasonable grounds to believe” that records are “relevant and material” to an investigation.)
Despite its conclusion that warrants rather than court orders are necessary for CSLI disclosure, the Fourth Circuit panel actually upheld the search. The judges found that the good faith exception to the exclusionary rule applied because the government acted according to what were then established procedures. But at least in the Fourth Circuit, the law is now clear, meaning that officers and prosecutors won’t have this “out” the next time they try to grab CSLI.
Conflict in the Courts
Despite the ruling, the law on cell location data is anything but uniform. Some state courts, including the supreme courts of Massachusetts and New Jersey, have agreed that inspection of cellphone location information requires a warrant. (Com. v. Augustine, 467 Mass. 230 (2014), State v. Earls, 214 N.J. 564 (2013).)
On the other hand, a Fifth Circuit panel ruled in 2013 that the government doesn’t need a warrant to acquire historical CSLI. And the Eleventh Circuit agreed earlier this year. These courts have theorized that people voluntarily convey their location by using their cellphones. (In re U.S. for Historical Cell Site Data, 724 F.3d 600 (5th Cir. 2013), United States v. Davis, 785 F.3d 498 (11th Cir. 2015).)
So, do the police need a warrant to see what your phone says about where you’ve been? That depends in significant part on where you’ve been.