So what? What do you suppose that proves or justifies or excuses?

The ID served a valid purpose of controlling who had access to beer, yet did not track anyone's movements or habits or compile a profile on them or associate them with others into cohorts or allow anyone to presume to make any kinds of judgements or predictions about them.

The two things are not automatically and necessarily tied. It's a disingenuous lie to act like they are and use the one to justify or excuse the other.

Indulging in a little predicting myself, let me guess what comes next, "But showing ID for beer never prevented every single underage human from somehow obtaining beer." ? Wait it was unfair for me to assume that based on some data I just collected (your comment)?

Have you traveled outside the country? Please share with everyone on HN the exact date and times, the street address where you stayed and the phone number of someone who can corroborate.

Can you think of any reason that this information shouldn't be shared publicly? Maybe post your phone number and we'll chat about it.

Many former Warsaw Pact citizens have lived under a surveillance state with a dossier on every citizen, and didn't find it particularly great.

Well, yeah, all of that presents a privacy problem. Automation is taking it a step further, but if I had my way boarding a plane would be like boarding a train or bus. I could concede a fast-moving checkpoint that does some best-effort scanning for firearms and blades or whatever as people walk through a gate, provided the data is verifiably shredded as soon as scanning is complete. This safety paranoia is not borne of genuine danger. People walk into more crowded and critical areas than planes with firearms all the time in the US. The only thing stopping frequent mass-casualty deaths is that most people don't want to kill a ton of other people indiscriminately, not the TSA.

Securing the cockpit doors on planes is a good idea though.