The NSA can (and does) use Facebook to mark you as a suspected terrorist and put you on a no-fly list. The NSA doesn't have the power to imprison you or seize your bank accounts without the help of a judge.
However, the balance of power in our society has now shifted to the point where the NSA is trivially capable of securing the judges' cooperation. So the "help of the judge" will be granted anytime the NSA asks for it, and in a practical sense they can still do all sorts of unpleasant things to you at will.
Also, if a judge starts being uncooperative, the NSA has a lengthy dossier on his adultery, homosexuality, communist tendencies, suspected terrorist links, etc. It would be a real shame for that dossier to find its way to the public, wouldn't it...?
