The U.S. government argued on Friday that it should be allowed access to people's cell-phone records to help track suspected criminals.

A Justice Department attorney urged a federal appeals court in Philadelphia to overturn lower court rulings denying it the right to seek information from communications companies about the call activity of specific numbers that authorities believe are associated with criminal activity.

But civil rights lawyers argued that providing information such as dates, times and call duration, and which cell towers the calls used, would be an invasion of privacy and a violation of constitutional protections against unjustified arrest.