Rio does graffiti like no where else. The level of precision and craft that you see is exceptional. Brazilian's have legitimized some of these more sophisticated versions of writing that are differentiated as graffiti as opposed to pichação which is a monotone simple writing form involving unique letters and glyphs that is an attempt to make a public statement on high, hard to reach surfaces. Pichação generally seen as a nuisance.
What if more of the surfaces of our public urban spaces were seen as a communal canvas that we all could share? It could be a constantly evolving conversation to which anyone contributes. It reminds me of yesterday's New York Times article "Graffiti of New York's Past, Revived and Remade" A collective of local graffiti artists have remade and paid tribute to famous graffiti across NYC from the past. A project they call "Subway Art History", and they have the permission from the businesses and schools that own the surfaces that becomes their canvases.