I want to emphasize, repeating what multiple people have said here, that you can decide what information to post on Facebook, therefor, Facebook, if configured correctly, will only show people information you allow it to.
My Facebook is set to private. I publicly share one photo, my name and who I'm friends with. Someone browsing my profile can then figure out if they know me and choose whether or not to add me as a friend, at which point I have the choice of ignoring them or accepting their request, in which case they can see what I don't mind sharing with an uncle, my parents, my best friends and all sorts of business contacts -not to mention ex-girlfriends and some people I don't really know that well.
Also, if some person or entity wants to figure out who I associate with, I really doubt they need Facebook to do it.
-Jonathan