In 2010 a court ruled against government requests for mobile location data, declaring that “[c]ompelled warrantless disclosure of cell site data violates the Fourth Amendment.”

On appeal federal prosecutors are asserting that they should be able to obtain records revealing the movements of mobile users over a 60-day period, even if the phones are off, without first having to ask a judge to approve a warrant.

The Justice Department argued in February that its position is "consistent with the Fourth Amendment because a customer has no privacy interest" in GPS location records since that information has been "voluntarily conveyed" to the wireless provider