Seems the UK has been delving beyond emails and has been looking at tracking your mood online as a determinant of potential criminality:
For the past two years, a secretive unit in the Metropolitan Police has been developing the tools for blanket surveillance of the public’s social media conversations. Operating 24 hours a day, seven days a week, a staff of 17 officers in the National Domestic Extremism Unit (NDEU) has been scanning the public’s tweets, YouTube videos, Facebook profiles, and anything else UK citizens post in the public online sphere.
Its actually pretty creepy. The process used is called “Sentiment Analysis” which
… can determine your mood, “horizon scanning” that tries to pre-empt disorder and crime, facial recognition software that can track down individuals, geo-location that is able to pinpoint your whereabouts, and profiling that can map who you are and what circles you move in. All innovative techniques used in the private sector, and all adapted for law enforcement and surveillance.
In short, everything we thought might have been true, is true. Why aren’t we fighting this?