Private companies are making money vacuuming up photos of things in the public realm, like license plates and peoples’ faces, and selling them to law enforcement. I think we have to accept that the technology of potential tyranny is here to stay, and in fact it is necessary in a world of mass shootings and potentially much worse things, like bioterrorism. We need to figure out a way to regulate and channel it to positive purposes in democratic societies, but we will never be able to make it go away or even slow it down.