FBI spots potential danger to a school – on Facebook

As opposed to my previous post, BBC reports an instance where the FBI has made use of public information to predict a possible threat to St Aelred’s Catholic Technology College in England.  The information was on Facebook, and was available probably because the defendant hadn’t protected his postings, perhaps due to FB’s confusing approach to privacy.  Imagine, however, that FB didn’t confuse anyone, and this information were protected.  Would the FBI have been prevented from warning St. Aelreds?  If if they couldn’t, would Facebook?  And if Facebook didn’t would the FBI insist on new powers?  Watch this space.