I suspect there are a significant amount of snap judgements being made, and I would be very surprised if they kept anyone safe. One of the many examples is that

I suspect there are a significant amount of snap judgements being made, and I would be very surprised if they kept anyone safe. One of the many examples is that when I traveled a lot, I quickly noticed that if I have had a recent shave and have my hair cut short (no longer than to the end of the ear) I do not get picked out. If I have long hair or a goatee, I will get picked out for extra questioning (dogs in bags, bomb swabs, extra-strict questioning by border officials, regular bag search, etc) every time.