What alas struck me as odd in Germany that after ww2 and the Stazi in east germany you still have manditory ID cards + registration when you move with the police! and you get upset about street view?
you dont have to tell the police when you move. only the local goverment (Einwohnermeldeamt)
In this context it sounds a little scary either way(don't the local police have access to local government records so same difference.) It could be quite innocuous, like being registered to vote, and needing to know in which local elections you can participate.