USA Today put up an article on Sunday detailing the process by which the FBI and even local police agencies can use hardware devices to mimic the NSA phone tracking methodology, but with cellphones.  The lead from the article:

The National Security Agency isn’t the only government entity secretly collecting data from people’s cellphones. Local police are increasingly scooping it up, too.

Armed with new technologies, including mobile devices that tap into cellphone data in real time …

The chilling details are HERE.