For either 18 months or 3 years now with Facebook's revised privacy policy. However when someone else posts an embarassing pic on their wall of you are most likely memorialized forever. And with the current state of facial recognition you are basically compromised. So next time you have a job interview.....be afraid.
By the way Google now has an even more frightening privacy policy. They have just centralized their data collection amongst all their products - google plus, search engine, google maps, etc. Unless you are very careful they will have an even better profile of you than facebook. But no, they haven't crossed the divide of specifically selling your unique data, yet.