There was a lot of hoo-ha and speculation yesterday after Mark Zuckerberg's official Facebook fan page was updated with an unauthorised post. At first Facebook declined to comment on what - at first glance - appeared to be an embarrassing security faux pas by Zuckerberg or one of his staff authorised to update the page. Understandably there was speculation that Zuckerberg or one of his colleagues might have had their passwords guessed or stolen,...