If you want to experience the 'chilling effect' of facial recognition first hand, go to a meaningful political protest in the UK. These are different to the circus-and-bread protests, e.g. complaining about Trump in some collective Pinch and Judy show.<p>With the more useful protest events numbers are smaller and those that attend aren't there just to post selfies of themselves looking good protesting at the bogeyman-du-jour on Instagram. Protesting against the arms trade or fracking will be getting yourself proper attention from the authorities. The police have the one tactic called 'the kettle' where they form a police line around all the protesters, then letting them out, one by one, getting everyone's photo. From then on you know that you will be in some special rogue's gallery, to be denied being able to work for the three letter agencies and other places in the civil service due to being a known troublemaker. They don't need to take your postcode or DNA, just that waltz past the camera will do. As you can imagine this has a 'chilling effect' and curbs one' enthusiasm for wanting to participate in the direct democracy that is so encouraged by our governments just so long as it is part of the 'Arab Spring' or other such nonsense.<p>Facial recognition for cows on the farm, that is a thing and also has applications for other areas, e.g. nature conservation, so there is nothing wrong with it for other species, putting them under mass surveillance and not needing the physical tags.