It will happen, and it will become a constitutional issue once it becomes ubiquitous enough. These systems will likely be networked together, building and shar

It will happen, and it will become a constitutional issue once it becomes ubiquitous enough. These systems will likely be networked together, building and sharing profiles on known undesirables such that they can be banned from most, if not all stores eventually. Once that happens, there will be a class of people who cannot legally buy food anymore, because to enter a store would be trespass.