He usually won’t. But say Facebook publishes the next great American novel, and little guy finds out. He sues, they lose, they have to stop publishing, they pay damages.
The only way the terms of service are binding is if you agreed to them. For instance, I can’t walk up to you and say, “If you look at me, you owe me ten grand” and then expect that to be enforced.
The TOS on a website is the same thing. It is close to what’s called an adhesion contract, where you really have no choice in the matter and no chance to bargain with them. You can’t really call up facebook and negotiate the terms of service, and it’s not clear that clicking a little box is equivalent to you signing a contract, especially when you likely didn’t bother to read it.
The efficacy of click-thrus hasn’t really been tested in court, and the one time that I am aware of where it was addressed, the court did not find it too persuasive.
So what I am saying is that Facebook can claim you gave them all these rights, but it’s not clear that their terms of service are really going to be upheld by a court.
Secondly, yes, the words of the company can be just as binding, or more so, than the text of their TOS. The law doesn’t generally let people say one thing, especially in a very public forum, and then do something else in court. If the CEO says “Our terms of service mean X”, and then goes to the court and says “Uh, we meant something different”, the court isn’t going to take that very seriously, especially where there is doubt as to what the language means, because a public statement is better evidence of the company’s thoughts at the time they made the contract than the statement presented in court, where they obviously have motive to be dishonest.
Finally, the TOS for facebook only includes facebook-related uses; publishing a novel isn’t really that sort of use, especially for profit. The bit about other people having to delete your stuff is a CYA for facebook to protect them from lawsuits if you take something down, but someone else has used it.