A graffiti artist paints over a poster on a brick wall .
Chances are slight that a graffiti artist is illegally paining over a poster on a building .
It is likely that a graffiti artist is illegally paining over a poster on a building .
Chances are slight that a graffiti artist is illegally paining over a poster on a building .
A graffiti artist is illegally paining over a poster on a building .