The swinish part wasn’t them checking my citizenship. It was being bombarded with personal questions AFTER presenting valid proof of citizenship (i.e. US Passport).
The purpose of the internal checkpoints is to check for citizenship, not to go on a fishing expedition. As a citizen, I shouldn’t have to account for why I choose to travel in my OWN country. And didn’t, despite what the pigs wanted me to do.
Your situation in Europe was different since you were a foreigner.