All you can do is be very vigilant and check for the things mentioned.
A work colleague was flashed by a speed camera that was semi hidden behind a tall hedge. He went back to the camera that day and set it on fire to destroy the evidence.
Now I don't condone speeding as I'd be the first to complain if a relative was hit by a speeding motorist but hiding cameras behind hedges is taking the piss.
I do get enjoyment out of seeing chavs getting pulled in by cops at the roadside tho, and the look on their poor little acne infested faces as the coppers inspect their Skip VTR
