This is one of the awesomestest and scariestest technology demonstrations I've seen in a long while: Georgia Institute of Technology's students are using CCTV video to map actual vehicles and people into Google Earth. Why is this scary?
Right now, all the data displayed is anonymous, which makes up for a cool looking technology. You could see a football game in real time or the actual traffic in your route to work. Eventually, you will be able to see clouds moving, the weather changing, and even birds move in real time.
Now, put on your tin foil hat and imagine.
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, provided that you have enough cameras along the way, 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. And let's not talk about RFID tags.
Of course, I'm sure that no government agency will be interested in using this for controlling someone's movements. Why would they?
Now, excuse me while I go pack and move to an island in the Maldives. [PopSci]