Usually graffiti is 'tagging' these days, where the yoof spray 'artistic' signatures. And then there are the artists who remain anonymous and their art is now collectable and expensive. In fact so expensive that if created on your own wall, it will net you serious money. Banksy is the man/woman I'm thinking of here.
And then there are the political statements. But what about anti-faith statements? Until recently, I'd never seen one of those. But in Brussels last year when we visited St. Michael and St. Gudula Cathedral the first thing we saw was this statement from the atheist faith sprayed on the entrance to the cathedral. Whatever your beliefs, to disfigure fine architecture like this is in my mind real blasphemy. What utter morons.
Shot taken on the Leica M9 with 35mm at f.11