A good test of the purpose for the cameras being installed is this: "Are the cameras clearly sign posted?"
Here in NSW, AU most speed cameras in high traffic areas are clearly sign posted, generally with 3 sets of big, can't miss them warning signs, especially on the motorways. This is about to change a little with our red light cameras being upgraded to digital "safety" cameras that do both speed and red light runners although they are still signposted. We are also about to get the mobile semi covert car based cameras again, but even they used to have to place a sign on the road to warn you.