It's about expectations. Facebook started out with expectations that it is a place where you can share things among your friends but not the Internet at large.

It's about expectations. Facebook started out with expectations that it is a place where you can share things among your friends but not the Internet at large. Now the game is changing. "You have opted into their service and you are paying with your information." -- The typical user probably doesn't see it this way. It's borderline unethical for the payment to be something the paying party is unaware of.