I am wonder if it can be called graffiti (even reverse), since the graffiti practices are more connected to identity struggles, that are subversive (clearly shown in the long story of modern graffiti – connected to social revolutions –the wall as the people’s paper, and later in early urban gang-tribal graffiti of interest by the art establishment – case Keith Haring and Jean Michel Basquiat).

Graffiti has, for instance, and illegal connotation. These new reverse-graffiti artists are more in a 'conservationist' tone; the are activists of some sort (even if they are doing it just for fun or artistic purposes), but, and is my personal take on the issue, they are not radical or anarchist as the older generation of graffiti-makers. That by the way were not artists- the art world of the 1980s, for economic and political issues, made them that.
mr