Making graffiti by cleaning dirty walls...! (http://www.youtube.com/watch?v=JwsBBIIXT0E)

that is impressive.

Interesting

Brilliant. The guy finds a legal and harmless way to put something interesting in a public place and they ruin it pretty much right away by cleaning something they haven't bothered to clean for years.

Tosspots.

Its pretty sad but sometimes thats the only way to get something done. (Cleaned,etc)