People say graffiti is ugly, irresponsible and childish... but that's only if it's done properly.

Brandalism Any advertisement in public space that gives you no choice whether you see it or not is yours. It belongs to you. It's yours to take, rearrange and re-use. Asking for permission is like asking to keep a rock someone just threw at your head.

When you go to an art gallery you are simply a tourist looking at the trophy cabinet of a few millionaires.

It's impossible to predict which paintings will last and which won't. In New Orleans I painted on a dilapidated shop in a street littered with abandoned cars and rotting mattresses, then two hours later the piece was gone. It turned out I'd picked the side of a crack house and the proprietor didn't like the attention.

I think its pretty clear that film is the pre-eminent art form of our age. If Michaelangelo or Leonardo Da Vinci were alive today they’d be making Avatar, not painting a chapel. Film is incredibly democratic and accessible, it’s probably the best option if you actually want to change the world, not just re-decorate it.

I’ve learnt from experience that a painting isn’t finished when you put down your brush – that’s when it starts. The public reaction is what supplies meaning and value. Art comes alive in the arguments you have about it.

On Painting Rats, and the Glorification of Them. They exist without permission. They are hated, hunted and persecuted. They live in quiet desperation amongst the filth. And yet they are capable of bringing entire civilizations to their knees. If you are dirty, insignificant, and unloved then rats are the ultimate role model.