For someone who doesn't believe in privacy, Mark Zuckerberg is awfully guarded. He has made Facebook public by default, and yet his own public posts are few, far-between, and tend towards the anodyne. Facebook's share-everything CEO even went so far as to keep his recent wedding a secret from his own friends, presumably to avoid public scrutiny. For all his bluster about public sharing, Zuckerberg reveals very little of himself. That needs to change.