alt Hacker NewsAre there places people can legally grafitti there? In a number of small towns there are unofficial grafitti rocks or walls in public view that redirects a lot of peoples mischief and desire to display public art. Nobody is in any actual trouble if they are caught painting it although you will lose your paint.
It might not be a total solution, but it could have a significant impact on grafitti other places.
There's Clarion Alley in the heart of the Mission, which I think is open to graffiti, as everything is plastered with it, most of it looking really nice. You can see it on Street View.