The Naughtiest Thing You've Ever Done

I was once expelled from a violin course in Concordi for throwing wet paper tissues at the ceiling of the girls' loo's. I don't know if anyone has done it, but you can throw them and they just make this great splat noise then stay there. The most satisfying thing you can do is to wet paper tissues and throw them at the ceiling. It's a sort of tame version of a dirty protest. And my gold medal goes to the doping cyclist. That's a genuinely good answer. Since you put everyone on the spot and the festival, it's your turn. What is the naughtiest thing you've ever done? Is the bar quite high? Do you