> Most large public services you use (Skype, Exchange, likely Gmail, etc) have backdoors.

Google gave up Paula Broadwell's joint Gmail account with David Petraeus to the FBI after receiving a subpoena. Gmail isn't secure unless you log in through Tor, compose your message on a separate editor (to avoid autosaving of plaintext) and then copy and paste a PGP encrypted message before you send it.

Now, you might think that this is a ridiculous and impractical thing to do, especially if you are not guilty of any crimes. But Paula Broadwell wasn't guilty of any crimes (or at least wasn't charged with any crimes) before Google happily violated her privacy by giving away her information without a warrant.