Facebook has changed their privacy settings, but this time they've eliminated the option to keep your page out of searches. This means that every member on Facebook will turn up in search results, even if they previously chose to not show up. This is largely linked to the graph search.
Leo suggests removing any personal picture if your name is fairly common, lock down your personal settings, and take out any way to contact you through the page. At least that way, you're not making it easy. If you really want to be anonymous, you can always delete your account altogether.