http://www.wired.com/wired/archive/12.04/start.html?pg=3

Issue 12.04 - April 2004
How to Stop Traffic

Floor it and say cheese. The Man saw you run that red light and has a picture to prove it. Cops say traffic cameras make intersections safer; opponents say faulty cams nail law-abiding citizens and that better engineering, like longer yellow lights, would actually stop traffic (which is the whole point). Prefer to opt out? It might be possible to hack a license plate - or traffic itself.

These devices might be illegal in your state. Wired didn't risk any lives to test them, and neither should you.