Are they taking info from people who specifically chose to allow only friends or family to see their postings? Or are they taking info from people who allow the public to see their postings?
Because if they are taking info from people who have blocked the public from seeing their postings, what’s the next step? Reading their e-mail?
That's what I would assume, if they are bothering to poke around. The "harvesting" and keeping may be as narrow as keeping what is deposited on WH-sponsored MySpace, Twit-pages, etc. That stuff (material sent to the WH) is supposed to be archived, according to law.
-- Because if they are taking info from people who have blocked the public from seeing their postings, what’s the next step? --
If they are poking into areas that a person is trying to limit access to, then I would find an invasion of privacy.