I've had related experiences in Germany. The police stop cars with no suspicion nor any explanation other than "police control". I told several German friends that this would be quite illegal in the US, and they were all shocked; it seemed normal and routine to them.
Denying the Holocaust and using Nazi symbols is illegal in Germany, but "papers please" is normal? I think they learned the wrong lesson.
Yes, it seems normal to me, unless it happens regularly.
I am now 32 years old. I have been in a police stop when driving my car only twice (and one of those was a mistake, I thought they wanted me to stop, but they actually meant another car).
I have never been controlled or ID checked by the police in any way when not travelling by car. Exceptions are border controls, of course. And private entities wishing to check my age: discos, liquor stores and so on.
On another note: I'm really tired about all this attitude we get from Americans regarding Nazi symbols and free speech. Maybe take a minute to contemplate why we have those laws?
"Because of Holocaust" is correct, but not what I'm getting at. We have those, because Americans (together with the other Allied Powers) forced us to after the war.
Unfortunately Americans have this tendency to think that their system is the very best and can't imagine why anyone could or should have another system, despite the fact that everywhere they were involved in nation-building they actively promoted other systems.
Denying the Holocaust and using Nazi symbols is illegal in Germany, but "papers please" is normal? I think they learned the wrong lesson.