You graffiti apologists just reinforce the general disrespect for other people's property that is already rampant. It's vandalism, plain and simple If it's not yours, don't fuck it up, how difficult is that? And why should there be a "legal" wall? You really think the people spraying this shit are going to say "oh, a legal wall, now I don't have to disrespect things that aren't mine!" How about the graffiti "artists" put a wall up in one of the vacant lots and spray on that? They can spend a fun day laying brick together, and when they're done they can spray their "art" all over it without destroying public property.