“Privacy Warnings” of one type or another have been making the rounds on Facebook ever since the site first came into existence.
While most of those warnings range from completely worthless to downright malicious, a few of them actually have some merit.
Privacy is indeed a serious concern on Facebook, but many folks understandably attempt to attack the problem from the wrong angle.

Have you ever signed up for a service online only to discover later that you had to call them up on the phone to cancel?
Have you ever considered how having your bank account could be a game-changer for your future career?