I "deleted" my FB after they acquired FriendFeed (still the best social network I've ever come across) back in 2009.
I was puzzled, then, to receive an email in November last year asking if I had tried to log in. "Impossible", I thought, "that account was deleted!". So, I visited Facebook, and because my old username/password were still in my password manager, I was able to log in! Imagine my shock to find my old profile, still there with it's old profile pic, my old connections, etc.
When will "delete my account" actually mean my account is deleted?
(The final kick in the nuts to this story is that within 2 minutes of logging in, I get a chirpy, "Welcome back to Facebook!" email. Fuckers.)