mainlymark.com

Imagine that someone is able to tag you in some way. In theory, it could be as easy as having access to one of the CCTV cameras and this system. You mark a car on the screen and the technology would be able to follow the vehicle wherever it goes. In England, for example, this will be really easy to do, because there are CCTV cameras absolutely everywhere.

Of course, I'm sure that no government agency will be interested in using this for controlling someone's movements.