I'm not sure what you mean by "Those in power" there are lot's of people who know, but recognise that he has chosen anonymity and see no value in putting a name to the person.

It's not so much a secret as it is simply not public.

Good. I'm glad most of the media have come to a gentlemen's agreement to not blast his name everywhere. Adds a little more fun to the world. Even this statute is staying for now, the local council, bless them, have decided to leave it in place for the near future.

Who cares? Are you similarly triggered by The Rock or Alemao? Banksy is Banksy.

Tracking Bansky is a favorite spy software sales demo given to authoritarian governments.

The point appears to have whizzed a couple of feet over your head.