Unless you want the government to define art there is no way to legally differentiate between someone making an artistic statement and simple vandalism.
Personally I'd rather outlaw graffiti than allow it anywhere, or have the government attempt to define it. Some places do permit graffiti on their walls so as long as you have permission it's fine.
Personally I'd rather outlaw graffiti than allow it anywhere, or have the government attempt to define it. Some places do permit graffiti on their walls so as long as you have permission it's fine.