Unlike speed limits which are arbitrarily set too low (and you know they are too low when nearly every single driver is disobeying the posted limit), traffic lights are necessary to regulate traffic flow when there is actually traffic at an intersection.
On the other hand, enforcement of laws via camera is a whole new world of big brother watching you. But in theory, the camera doesn't see anything that a cop hiding near the intersection wouldn't have been able to see. I'm sure thats what the courts have held.
Technology allows better enforcement of existing laws. Enforcement of just laws is good (like red light running or murder) but enforcement of unjust laws (like speed limits or drug possession) is bad.
But the thing to fear is that the government could uses its new powerful information gathering ability for bad purposes such as rooting out and arresting people for speaking out against the government. The reason why the Second Amendment was placed into the Constitution was to give ultimate power to the people in case they needed to rebel against the government. Technological law enforcement, like removing people's weapons, makes a future revolution that much more difficult if not impossible.
Unfortunately, the technological genie is out of the bag and can't exactly be put back in. I predict an ever increasing use of cameras and other technology with only a tiny percentage of people complaining about it.