Everyone's got annoying Facebook friends, whether they're annoying everywhere else or the site just transforms them. You could unfriend them, block them, or report them to the Facebook authorities, but then you'd have to avoid them in real life as well.
A better option is to send them to Defriendtion, a hilarious pun on detention and friend, also a new Facebook app that finally gives Facebook users something similar to what they've been asking for the most, a dislike button.
It's just as harmless as a like button as well, which is probably for the best. The app posts a notice on their timeline and on your news feed; it's a fun way of getting back at your friends without actually taking any drastic measures. Oh, and you can post about it on Twitter too.