I know there has been a lot of talk about redlight cameras and their use to increase roadway safety or their use to make a profit. I have always heard redlight cameras were for safety and not profit.
Slashdot linked to an article about 6 cities tampering with the length of the yellow light in order to catch more redlight runners. The original report detailing the 6 cities that tampered with yellow light timing is here.
Update – Ars Technica has a good overview of the story.