Oldtimerkennzeichen jetzt auch als Saisonkennzeichen

[Don Rocket]

I can walk up to your car and check HU and tax status by looking at the number plate that has to be displayed. So it is public information.

Yes, yet debatable
You have to make a physical effort to actually go and see the car. This is different to an online information that is public to the entire world.

Same for private homes; of course you could walk past my house and check on the address and name on the door. But you won't find my name in any public telephone book.
Germany is one of the few countries where you can force Google to blur your house on Google Street View and that's just fine.

Anyway, I am going off-topic here...

Have a nice weekend!
Cheers
Dieter