Artistic with a can

I'm a fan of graffiti, not the badly scrawled gibberish from some pathetic low life with nothing better to do than paint "M Khan is bent" on a wall (thats an 80s Mary Whitehouse Experience reference for those old enough to remember the comedy show!) But something with meaning, something that brightens up an otherwise dull part of a town. A couple of years ago we trekked all over Brighton checking out the art work on the walls, it was fascinating. I was taking a shortcut down an alley in Tooting when I spied this, too big to get in one photo, it stretched for probably 30 or 40 metres down the wall.