If you want Gmail to act like a post office, treat it like one: fetch the emails on your computer, keep an archive. I pop my mail (pop(keep off)->spamassassin&

If you want Gmail to act like a post office, treat it like one: fetch the emails on your computer, keep an archive. I pop my mail (pop(keep off)->spamassassin&clamav->maildirs, via procmail) and my archive is on my computer, so whatever service I use can't do anything with it. AFAIK there are software to fetch from IMAP too. With Facebook, well, I guess you agree to them being able to delete your data at their will via the little box you tick on sign-up. And as long as you accept those terms, law won't help.