I love street art. Sometimes it's just for the simple graphic and other times for the statement they make. Artists like Alexandre Orion and Moose have have a unique way of creating theirs. Instead adding paint to a wall, they do reverse graffiti or "green graffiti", a method of creating temporary or semi permanent images on wall by removing dirt form the surface. When they first started they were challenged by authorities, but what could they do arrest them for cleaning? Pretty cool.