I used AIM from not long after its inception in the very late 90s up until this year when I finally uninstalled Pidgin a couple months ago. Probably one of the very few people around that can say that.
Back when I was a lawless teenager I once used a web exploit to steal the "AOL System Msg" account that IMed you whenever you signed into an account at multiple locations. I used it to send my friends a bunch of messages saying they had been signed on at 500 locations or something crazy like that.
AOL suspended all my accounts (and everyone on my buddy list, ask Tyrath) within 24 hours, lol