Organizations with extensive hacking resources can, and probably do, clone phones. But the ability to clone one phone via another quickly and wirelessly is not possible as it is depicted in Person of Interest.

Phone apps, such as , , , and others work invisibly in the background and handle several types of espionage, including real-time location tracking. After the software is installed on an individual's phone, you can watch on a map as he roams around town.

But these apps need to be physically installed on a phone. To the best of my knowledge, they can't be installed remotely, though it's possible that the user could be tricked into installing software with similar functions. This could be done by spoofing a legitimate app, for example.

However, a spy organization or government agency wouldn't need to install an app on your phone to track your location. They only need to gain access to the location tracking that your wireless carriers already do.