Who's Tracking Your Cell Phone?

Is your cell phone being tracked? The odds are quite good there's a spy in your pocket. The only real question is, who's doing it?

Earlier this week Wired's Spencer Ackerman profiled what he calls the "Keyzer Soze" of geo-location tracking, a company called TruePosition. TP uses cell tower triangulation to locate the geo position of any cell phone within 50 meters.

This technology is used for e911 calls in the US by T-Mobile and AT&T, so if you're in trouble the good guys can find you. It is also used by foreign governments for purposes known only to them (but presumably not necessarily the good guys). Using TruePosition, organizations can create a "geo fence" around sensitive facilities like nuclear power plants. If someone with an unauthorized cell number enters the geo-fenced area, the authorities can receive an alert and intercept the interloper.