The usual stuff you do on facebook, add a bunch of friends, reply to "important" messages, posted wall comments on groups, play poker, posted comments on other people's news feed. here you go http://www.facebook.com/terms.php
Back when I first started out in internet marketing, I tried the dirty world of e-whoring on Facebook. Had eighty plus accounts started up, and a team of thirty working on them all, and then one day the slew of them were banned. Went from $1,000+ profit a day to nothing. Yes, I have been banned on Facebook.