I wouldnt want to be remembered as the guy who contaminated a perfectly legitimate form of protest art with money and celebrities.
There's nothing more dangerous than someone who wants to make the world a better place.
Keep your coins, I want change.
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 don't think you should have to pay to look at graffiti. You should only pay if you want to get rid of it,