Hooligans in Hamburg, Germany managed to sneak into a train depot and decommission a vehicle by barricading one of its doors with bricks and sealing it with expanding foam. Stupid and funny as it may be, the damages are in the thousands of dollars.
Glitter Bomb just a little too evil for your tastes? Goat Attack allows you to bombard your friends with 14 goat images and puns for the cost of $1.19 or a smaller six-message package for $.79 (a Goat Offensive, maybe?).
Combine this with a custom subscription to Cat Facts and you're basically guaranteed to make your friends go insane.