I'm not sure about the camera's, but speeding tickets as revenue boosters is a subject that's quite an issue in Oklahoma. Very small towns were raising a great deal of money by ticketing motorists in interesting situations. Oklahoma isn't as sparse in population as Montana however most of the poplulation is concentrated in two major areas. So most of these small towns were ticketing folks in the middle of nowhere, generally where the speed was not causing any real problem. The state legislature recently passed a bill greatly increasing the requirements placed on local jurisdictions concerning speed postings and other warnings. They also placed a percentage cap on the amount of revenue a town could raise through ticket revenues.