Yeah, so um... Probably not a good idea to vandalize, at least not in the form of monetary damages. Maybe something that wouldn't damage anything but cause a lot of mental suffering, if you must, but I would suggest against keying his car, etc.
You could put some crap in a bag and light it on his doorstep, then potato knock him, lol.
Or you could get a potato gun and shoot eggs from far away. If you don't have a spud gun then build one, you will love it, so many awesome uses. I still need to get mine fixed.