So the Met police have software that collates and analyses your digital footprint or shadow: Guardian article
Well really how powerful can that be? Surprisingly - according to Wall Street Journal (preview free)
They cite; research at MIT that can predict if you are getting flu - just from your behaviour pattern as monitored by your phone, a project at the LSE that indicates that "The most despondent place in the U.K. is an hour or so west of London, in a town called Slough.", and the impact of the language divide in Belgium.