[RoadKingSE]

I've often fantasized about taking out those traffic cameras by decorating their lens screens with some spray paint or a few well placed rounds from a paint ball gun.

This looks like a job for Carl Spackler.

[aruanan]

I've often fantasized about taking out those traffic cameras by decorating their lens screens with some spray paint or a few well placed rounds from a paint ball gun.

No, either of those would be readily detectable. You need to put a fresnel lens over the light source for the flash. To anyone standing there looking at the flash, it would appear to be functioning but the lens would diffuse the light enough that it wouldn't be sufficient to illuminate the license plate at a distance.