People who believe we aren't a legit nation and think they are still citizens (Bürger) of the Reich instead of the Republik.
Thus being opposed to everything concerning the government, be it police, taxation, IDs, you name it. Obviously a perceived overreach like its happening now will trigger those folks hard.
It is based on the standpoint that our current constitution is not valid, since the Weimarer constitution from 1919 was not ever officially scrapped, not by Hitler, and not by the Allies either. Which would mean de jure the Reich only is in existence, and everything that involves new constitutions after it is null and void.
However, it's not a homogeneous group, there are rather small groups or single persons affiliated by this common belief, and their common love for jet-boats. Most think it's still the Kaiserreich (before ww1), others the Reich from 1937, and still others think they can just claim this somehow and "quit" citizenship via a letter and stop paying taxes n stuff.
Other factors are the two constitutions we had in West-Germany and East-Germany, that both said only they represent the whole nation and all its citizens, and that after reunification there has not been a newly crafted constitution (the western one was just taken).
Constitutional judges have said everything is in order since the old constitution has been replaced and our constitution now is the one tho.
So it is complex law stuff with a lot of technicalities in play, that some people use to create alternative realities for themselves.
