<http://schema.org/about>
"\"The shape and text was created by power-washing filthy sidewalks using a large stencil form. [..] Sidewalks are usually very filthy and just the thought you could make your point by creating a clean spot instead of a dirty one is one to cherish. This"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/culture/air-pollution-guerrilla-marketing-in-chicago.html>