They tried having photo cops on Route 80 in NJ back in the late 80's or early 90's (don't quite remember) and it was simply a camera sticking out of the back of a van. Trip the speed limit, take a photo of the driver, mail summons to person. From what I remember at the time, it caused a bit of an uproar after a few politicians got pictures of them driving with their mistress and the summons envelope being opened by their wife.
Speed enforcement is fine; it keeps people relatively sane with their driving habits. I personally feel that the dangerous ones on the road are the ones who are driving more than 5-10 mph away from the average that everyone else on the section of road is driving. But sometimes you have a clear shot where there is nobody around you and goosing it up several mph to gain some time isn't that big a deal. If an automaton is going to penalize me without any context, that's where I draw the line.