Appeals court to review standards for cell phone data requests by government

In a case with broad privacy implications, the Court of Appeals for the Third Circuit on Thursday will hear arguments on the minimum legal standards that prosecutors need to meet when requesting cell phone location data for law enforcement purposes.

The case's prosecutors have argued that to ask for data they only need to show "reasonable cause" to believe that cell phone records are relevant to an ongoing investigation. But several lower court judges and a coalition of privacy groups are arguing that authorities need to be held to the more stringent "probable cause" standard when asking for such information. The case is important because it is the first time a federal appellate court has been asked to decide on the legal standard the government needs to use when requesting cell phone data, said Jim Dempsey, vice president for public policy at the Center for Democracy and Technology (CDT) in Washington. The CDT has filed an amicus brief in the case. "We think the location information generated by your cell phone paints a very complete picture of your life even if you are not making a call," Dempsey said. "The premise of our argument is that cell phone tracking data is uniquely pervasive, persistent, intrusive and revealing."