I suspect that this will never happen, because someone is bound to get in a tiz about Banksy never having asked to paint on anyone’s walls. And no doubt a conservative from one of the city’s wealthier boroughs, which probably has no graffiti whatsoever, will complain that it is a ’graffiti artists charter’, or something like that.
I rather like the idea of protecting Banksy’s works, though I think selling Banksy’s through Art Gallery’s with ‘house attached’ is perhaps the way to go on this front.
As for Banksy himself?
I think he would be his usual consistent self and say something like:
“If you don’t like it ,paint over it.”
He has said it in the past.
And we would still have the photos, though I have noticed that a lot of people who take photo’s of Banksys work get quite proprietorial over the copyright on their pictures.
Which is interesting, and raises all sorts of questions, about claiming ownership of a reproduction of a ‘free’ public art work.