You've hit the nail right on the head. Googling one's name will give you your Facebook profile (should you have one) near the top of the list. Ever notice hits for getting internet info for your name right under it? More often than not you have to pay them, but more often than not that info will include your current email address.

Docs.com has a partnership with Facebook in that when signing-up your Facebook profile info is shared. All of it. There's a pop-up that notifies you, and you can opt-out, but you lose the single sign-on advantage. Currently there are no settings to allow you to filter this information including information gathered by other Facebook apps and partnerships you use no matter how unrelated, but Facebook shares it with everyone else. So you share a presentation or file via docs.com to a business colleague or client, and /now have access to your Facebook profile without being added as a friend/. For free.

There are also /many/ documented examples over the years by CNET, dice.com, and games-related sites of employers using Facebook for background checks. It was once suggested that gamers in general not emphasize their game playing on their MySpace or Facebook pages. We are often percieved (MMO players most of all) as not being able to properly prioritize our time. Such as playing WoW at work.