they may want it and they may claim they've got it but I highly doubt it would fly. The manufacturer of the paper you write on does not get to claim copyright, you do.
Yeah. They're very "You're not allowed to get mad at us if your stuff stays on the database after you're gone, because it's really hard for us to make sure it all disappears." If you're paranoid/have never used a site with TOS, that sounds like "We want to steal your creative ideas," but I assure you that if Facebook ever did something like that, they would get pounded hard and lose users. HN had this exact discussion with the Gmail TOS, I believe, and people were worried that Google would be stealing their emailed poetry.
Sites really aren't evil. You've got to trust me on this, most sites aren't saying "How can we potentially steal a million dollars in the off-chance that one of our users posts up a movie script as a note rather than, say, sending it off to an executive?" Rather, they're saying, "Look, we're getting a lot of people who're being dicks about how we keep their data so that if they want to return their account magically comes back, and we think that it's better to keep that data than to remove it, because that way the people who delete accounts stupidly can come back and be happy they don't have to start again. At the same time, it's true that we're retaining data we shouldn't retain. So let's just add to our TOS that we're allowed to do that, since most people won't care, and since it means we can provide a useful service that'll help more people than it will piss off."
