I don't touch anyone else's ride without approval, and I don't expect anyone to touch mine. I may stop just this side of ballistic, but they will think twice before they do it again! Reminds me of a commercial I saw for Dockers. This guy was sitting on someones bike and broke the mirror. The guy catches him, says "Nice Pants" and then rides off. As the shot pulls away you see the mirror breaker standing there in his underwear! That could work!