"Likes" on Facebook tell your friends what you, well, like. But they may also tell people things that you might not like them to know, such as your sexual orientation, political views, alcohol and drug habits, and even how smart you really are.
In a study published in the March 11, 2013, Proceedings of the National Academy of Sciences, researchers from Cambridge University and Microsoft probed the likes of more than 50,000 Facebook users and found that they revealed information about a wide range of personal attributes that most people would think are private. A user who likes "Dear Liver Thanks You're a Champ" is not being coy about his appreciation of booze, but a thumbs-up on "Watching Karma Bite The Person You Hate Right In The Ass" is also associated with alcohol consumption. On the other hand, liking "Why Is Monday So Far Away From Friday And Friday So Bloody Close To Monday" is associated with Facebookers who don't drink. Smokers like "Under Armour" whereas non-smokers like "Honda."
The researchers found that likes also correlate with personality attributes. Extraverted folks like "Beerpong," whereas introverts like "Programming." People who enjoy "Curly Fries," "Thunderstorms," and "Morgan Freemans Voice [sic]" also tend to have high IQs. The researchers predict that ever more subtly revealing digital correlations will become much easier to discern, prompting them to worry that in the future "such predictions, even if incorrect, could pose a threat to an individual's well-being, freedom, or even life."