I used to work with a really annoying person who used to come to work on his motorbike, when he arrived at work he changed out of his motorcycling gear and into his work clothes and used to leave his motorcycle boots on top of his locker. One day he had really wound me up so much, so I went to the lo the locker room, took his boots from the top of his locker and put my tuna sandwiches into the bottom of his boots.....he never left them on top of his locker again. I feel such a bad person recalling that!