This a must read post on how a couple of kids had their inequalities exposed by Facebook even though they did everything humanly possible to protect themselves. Regardless of what you think about homosexuality, this isn't a post about that.
Rather, it's about social networks, specifically Zucker's Facebook, to continue "zuck" its users over time by shifting privacy goal line by giving the illusion of providing users with more controls while leaving loopholes on others.
For instance, if a friend tags you in a photo, there is absolutely nothing you can do about it. And anyone can just decide to sign you up for a group without your explicit consent. And the news of that will be open for all your friends and family to see.
That is the basis for a couple of college students who were outed by Facebook when someone enrolled them in a gay chorus.
It's a must read post regarding the shady practices that Facebook uses to screw and put a dollar sign on its users.