Again, I've posted it before, but...
Not me, but I heard tell of a guy at college who, being immensely anal, was plagued by people breaking into his room and messing it up. Just for the fun of it. And of course the angrier he got, the more fun it got. The more security he tried to apply, the more interesting the challenge became. No-one ever took anything - just messed things around a bit. Eventually he cracked and hired a firm at great expense to install a massively solid, massively costly special security door. Returned after a weekend away to discover his room immaculate - exactly as he'd left it. The door was missing, mind...