> German train crews relentlessly checking and re-checking and re-re-re-checking
That's done every time a crew changes. The same crew does exactly check you once, but they go multiple times through the train.
This has nothing to do with immigration or crime. Train crews have no authority of the police.
> At the first stop inside the German border, police -- that is, officers in uniforms which read POLIZEI -- boarding the train and carrying out a check of every passenger's identification. This was not a ticket check, it was an identification check.
That happens randomly or during special tasks. There are also police checks on the road near borders, where they check some cars they find interesting. Sometimes they also do coordinated searches for drugs, stolen cars, ...
Targets are illegal immigrants and criminal activity.
> the purpose of my visit to Germany and the duration of my stay in Germany. This was asked despite my already having legally entered and having remained continuously within the Schengen area (my passport, already displayed by that point, contained the entry stamp, ironically from an airport in Germany), and despite my already having entered Germany twice on that trip.
These are standard questions of every kind of border control. It's just that in the Schengen area the controls between member states are more or less random and not necessarily at the border.
Some people may never see a border control and others might see it more often. But for somebody from Poland entering Germany, the checks are only to have an eye on criminal activity. Other than that polish persons can freely move and work in Germany according to EU law. A lot of them work here. Legal and illegal. Illegal is work, if the work is not official registered, no taxes are paid, etc.
> As a result I am extremely skeptical of the idea that Germany has an "open border" or "no border controls" for intra-Schengen travel.
You can imagine that criminals are much more clever than you when it comes to avoiding the few random controls... they also have people broadcasting any police activity. A patrol on the train? Leave the train and take a private car over the border using a small street somewhere...
Keep in mind that perception matters a lot. This is, for example, a big part of how the TSA obtains "cooperation" from air passengers in the United States -- even though they aren't law enforcement and can't perform law-enforcement tasks like arresting people, everything about the way they present themselves (uniforms, badges, etc.) is designed to create the perception that they are and they can.
So if I'm on a train and it stops at the border, and a uniformed government official comes in and asks to see my passport and then starts asking me immigration questions, the perception is not "this is an uncontrolled border, just got a random check that could have happened anywhere in the country". The perception is not "oh, this officer can't actually deny me entry".
The perception is "this is an immigration check at the border", and the dynamic of the situation flows from there.
The ticket checking by rail crews does seem to be an entirely German thing (again, other countries' rail crews just had a list and marked which seats had been checked, so even if another crew or crew member came through later they didn't need to repeat it), and I suspect there's a larger cultural pattern here tied into things like the German identification-obligation laws (which, to be honest, made me more than a bit uncomfortable when I learned about them -- I have enough trouble with the idea that in my home country courts have ruled I can be subjected to an ID check at any time, learning that it's still a deeply-ingrained thing in a country with Germany's history is off the scale of unsettling for me).
> So if I'm on a train and it stops at the border, and a uniformed government official comes in and asks to see my passport and then starts asking me immigration questions, the perception is not "this is an uncontrolled border, just got a random check that could have happened anywhere in the country". The perception is not "oh, this officer can't actually deny me entry".
If you travel in a foreign country, you might want to make yourself familiar with the usual regulations.
> The ticket checking by rail crews does seem to be an entirely German thing (again, other countries' rail crews just had a list and marked which seats had been checked, so even if another crew or crew member came through later they didn't need to repeat it),
> German train crews relentlessly checking and re-checking and re-re-re-checking
That's done every time a crew changes. The same crew does exactly check you once, but they go multiple times through the train.
This has nothing to do with immigration or crime. Train crews have no authority of the police.
> At the first stop inside the German border, police -- that is, officers in uniforms which read POLIZEI -- boarding the train and carrying out a check of every passenger's identification. This was not a ticket check, it was an identification check.
That happens randomly or during special tasks. There are also police checks on the road near borders, where they check some cars they find interesting. Sometimes they also do coordinated searches for drugs, stolen cars, ...
Targets are illegal immigrants and criminal activity.
> the purpose of my visit to Germany and the duration of my stay in Germany. This was asked despite my already having legally entered and having remained continuously within the Schengen area (my passport, already displayed by that point, contained the entry stamp, ironically from an airport in Germany), and despite my already having entered Germany twice on that trip.
These are standard questions of every kind of border control. It's just that in the Schengen area the controls between member states are more or less random and not necessarily at the border.
Some people may never see a border control and others might see it more often. But for somebody from Poland entering Germany, the checks are only to have an eye on criminal activity. Other than that polish persons can freely move and work in Germany according to EU law. A lot of them work here. Legal and illegal. Illegal is work, if the work is not official registered, no taxes are paid, etc.
> As a result I am extremely skeptical of the idea that Germany has an "open border" or "no border controls" for intra-Schengen travel.
You can imagine that criminals are much more clever than you when it comes to avoiding the few random controls... they also have people broadcasting any police activity. A patrol on the train? Leave the train and take a private car over the border using a small street somewhere...