In Toronto just north of Bloor between Keele and Dundas there are a number of buildings with their backs facing the subway line - which is out in the open for a short stretch. Graffiti artists have been decorating these buildings for a big audience of commuters for at least fifteen years that I know of, quite possibly considerably longer. At this point it's institutionalized. The "wallnoize.com" domain is for sale, don't bother typing it into your browser.