Companies like Facebook base their income on the information they collect from you, and are therefore in a continuous arms race with you to lure you into giving out more information. I admire your absolute understanding of privacy choices on every level and nuance imaginable, but most of the other people in this world are less aware and more easily tricked... and even if they are rather smart, they make mistakes.
Is it therefore fair to put the onus on the person who has a Facebook profile to protect their privacy? Especially when the founder of Facebook has been on record a few times, stating that privacy is on a slippery slope anyway, and they'll just go with the flow? Especially when the "I've got nothing to hide" argument has been thoroughly debunked, because just about any information can be (selectively) used to incriminate you, even when you're entirely innocent?
As much as I am a fan of individual responsibility, I do believe that this tit-for-tat game of deception between social networking sites and their users is rather immoral on the side of the social networking sites, and that it is a cop out to say that the user is being stupid. This is where Assange draws the line, which is not paranoid, but realistic. They really are after eroding our privacy.