It's in our nature to play mean-spirited pranks — their secret appeal is that they make us feel powerful. Whether we're throwing a scare into someone we know is bound to panic, or merely engaging in mindless vandalism, we're in charge. We get to say how much gets destroyed or how far the prank goes. There's something deeply satisfying in leaving a big mess, then snickering behind our hands as others try to figure out who the perpetrators were.

But what happens when the pranks get out of hand, when real harm is done? Sometimes the jokes turn ugly.