I think street art and graffiti are different, Ronald. To me, graffiti is tacky, often vulgar, and diminishes what's around it. Street art is true creativity, even when it's controversial. My opinion.

My city solved many of its graffiti problems by designating two walls as canvases for public art, comments, ads, etc. Trash cans were provided for the used paint cans and other art supplies. No vulgar language or drawings are allowed; there is a police patrol who will paint over anything vulgar. The walls are art-in-progress - always changing. It's fascinating to see how different they look from one day to the next - sometimes from one hour to the next.