Imagine going to a peaceful protest and having to show your ID to the police before you can join it. Or having to fill out a form about why you are attending that particular protest.Sounds absurd, right? Surely we should all be free to protest, without the police knowing who we are?But high tech surveillance of protests is real, and it enables the police to identify, monitor and track protestors, indiscriminately and at scale.For example, your face is increasingly becoming your ID card with the…