scary thing for the UK. You have at least 25% 3,000,000+ of the worlds CCTV cameras, and the latest development for those is Gait DNA, which can recognise you from how you move, not just what you look like.
http://news.bbc.co.uk/2/hi/programmes/from_our_own_correspondent/6995061.stm
http://news.bbc.co.uk/2/hi/programmes/from_our_own_correspondent/6995061.stm