how many times must it be said that you don't put anything on the internet you don't want to be public. forget privacy settings, just assume everything is there for the world and his wife to read.
and in the case of facebook in particular, with all the shit flinging done about it, you must have been living under a penis shaped rock on Mars for the last 2 years if you were not aware that all your supposed private information was public, add to that the fact that mankind does not currently have the technology to put man beyond low earth orbit, there is no excuse for not being aware that Facebook security is a joke.
simple. Just assume every bit of information you put on the internet is public.