There are an awful lot of things that are on the verge of being all connected together and becoming interrogable. It’s happened in the spook sector already, in bits and pieces. Trapwire, a “threat mitigation system”, uses camera surveillance and data-mining to look for “pre-attack indicators”. Reportedly, it’s not hooked into a facial-recognition system. Of course, if it were, it would probably also be wired to one of the biggest public repositories of tagged faces in the world – Facebook.