Graffiti can be seen as an act of vandalism, the destruction of property, a crime. However, this small group of artists seeks to document graffiti because they view it as a youthful expression. Graffiti as a phenomena is a rebellious act, however it can often produce beautiful works of art. Because it can be considered a crime, the documentation of these works is not common. People "clean up" cities by removing graffiti, restoring plain brick walls to plain brick walls. I believe that graffiti makes certain areas look nicer, or at least certainly more interesting. I don't condone vandalism, and I would be upset if my house were vandalized, but I would eventually like to paint the outside of a building for the world to see my work.
