Senator Patrick Leahy is pushing to reform the Electronic Communications Privacy Act. The Vermont Democrat recently introduced legislation that would require law enforcement to obtain a search warrant to access personal communications and current location data from mobile devices.
As reported by Declan McCullagh of CNET:
… one important exception maintains the status quo: it does not require a warrant for police to peruse your historical whereabouts obtained by recording the movements of your cell phone, even if the location data are only a few hours old.
After his speech, Leahy told CNET that the exception was included to address law enforcement concerns.