Ever want to know who's looking you up on Facebook but not requesting you as a friend? Just click on "People You May Know" on your Facebook's homepage.
Facebook draws these "People You May Know" from several different sources, not just your email contacts or address book.
"People You May Know helps you find people you are likely to know. We show you people based on mutual friends, work and education information, networks you’re part of, contacts you’ve imported using friend finder and many other factors."
The most obvious of these other sources, and least controversial, is people with whom you have mutual friends. Some kid who has 45 friends in common with you is most likely someone you know.
Then of course, Facebook knows who works at the same company, or goes to the same school as you, from the info that appears in your profile.
Perhaps less obvious, they also know your IP address, so people using the same internet connection as you may pop up (now you know who's stealing your WiFi.)
However, you may notice suggested people with whom you have no mutual friends. People who aren't in your address book. People who share no school or affiliation that you've listed on your profile. People who have never used your internet connection. You may notice, though, that some of these people do, in fact, look familiar. They may be an acquaintance, a waiter at a restaurant you like, your landlord. You don't even know their last name! How the heck did Facebook know they might know you?
Does Zuckerberg have a zeppelin in the sky from which he watches and records our every human interaction?
Possibly. But that's not how they come to suggest these people. They suggest them because that person has searched for your name on Facebook. According to the internet message board chatter.
Take a moment for that to sink in. Now recall all the people you may have looked up on Facebook, including ex-girlfriends, the hot barista down at the Starbucks, that guy who lives in apartment 12 B. If you typed their name into Facebook's search box, you will pop up on their "People You May Know" list.
Just remember, when you search on Facebook, you're not searching anonymously. You're tipping off whoever you're searching for. You're letting them know you've been looking for their profile.
Rumors are circulating that Facebook is even sending emails to these people, saying that you'd like them to join Facebook. While not confirmed, this is pretty alarming.
Up until now, most of the warnings surrounding Facebook have centered around the information you choose to reveal. This however, goes much deeper-- Facebook using information you had no idea was being revealed at all... and giving you no choice to protect your privacy.
