FB is one of the biggest and worst of the social sites. People blindly give information thinking only ones they want will see it.
Ever read the agreement?
Carnegie Mellon researchers determined that it would take the average person 76 work days to read all the privacy policies they agreed to each year.
Nothing is yours once you post it on FB. They can sell it or use it anyway they want.
They sell access to businesses HR departments and others for gathering info on potential employees or current ones looking for a promotion or new job.
The new tracking software included in the mobile app is removing all privacy and people are clueless.
The huffingtonpost article on FB is very very interesting. Didn't Read Facebook's Fine Print? Here's Exactly What It Says | HuffPost