[Excerpt]: "Facebook insists it is up to you to decide how much you want others to see. And that is true, to some extent. But you cannot entirely opt out of Facebook searches. Facebook, however, does let you fine-tune who can see your “likes” and pictures, and, to a lesser extent, how much of yourself to expose to marketers.
The latest of its frequent changes to the site’s privacy settings was made in December. Facebook is nudging each of its billion subscribers to review them."