[alkonaut]

I'd be very surprised if Facebook didn't know my parents' names, my kids names, my shoe size and any other piece of information I haven't provided explicitly.

Just assume that anything that you entered on any website, or that you mentioned directly or indirectly to anyone on Facebook is available to Facebook.

In the creepiest of worlds I imagine this: on a non FB website with a FB "share" button on it, I congratulated a friend on her birthday five years ago. When she gets a FB account for the first time tomorrow, Facebook already has her shadow account with good Guesses of her details, including the birthday and real name.