< HowTo
Either use a laser to temporarily (or permanently, if you use a strong laser) blind the camera as described here or choose one of the more drastical procedures propagated by Rtmark in their guide.
A possibility not described in either of those guides is the use of a paintball-gun. (I remember to have read an article about some group in London who used some kind of a paintball-gun that's normally used for marking cows.)