Yeah I was going to ask you if you're familiar with him because he's probably the most well-known street artist in the world. He used to be really respected, and now I think people consider him hack.
For the longest time he remained anonymous.
Gang graffiti is also a thing, and usually it's different from the artist stuff.
It was really big in 90's especially in California, and NYC.
I think plenty of people have known who Bansky is for years, but does it really matter. His art can make people think and that's what it should do. It can just be a hassle if he paints on your property.
Graffiti can stray into vandalism, but there are places where street art is accepted and celebrated. I guess some prefer to be more outlaw about it.