These are fair as long as they play by the rules also:- Not parked on double yellows, bus stops, too far away from the road they are fixed on, cross hatchings, the list is endless as to where iv'e seen them parked. The fact is, if you get a ticket & the van or whatever is parked illegal then you can contest it.
The equipment also has to be calibrated & have a cert to say so.
These things iv'e learned from particular sites on the web.
Not True, if in London, I recently did some contract work in a building in Victoria, cant say too much but there are 3 floors just dedicated to replaying Camera Videos from VHS back up tapes, I was really surprised how many high building cameras there are covering London, say for example only, about 12 per set of traffic lights!
I couldn't belive the Camera quality, and the ability to zoom into a Number Plate with such high definition, from a VHS tape (taken from the main Matrix Server).
So, if the laser didn't get you, or the Number reconition white Van, believe me these Guy's will, there main concern is backing up so called 'it wasn't me claims' and of course other threats!.
I was quite impressed with the abillity that already exists!