This is the reason I have been wary of Facebook and all the Google connected social networking Internet sites, NSA can't hold a candle to these sites for their unrestrained information gathering practices. I was once the proprietor of a blasting business, explosives expert was one of the many hats I wore during my career, unbeknownst to me Google took it upon themselves to post that information along with a map to my home address. I had to convince the originator that they had endangered me and my family and that they would be legally liable and culpable if any harm should befall us, Google finally removed it. Here's a link to a recent article of how Facebook users are being studied like guinea pigs.
http://www.today.com/tech/users-angered-facebook-emotion-manipulation-study-1D79863049