Graphological anarcho futurists stand by. There's a new form of short range laser graffiti tagging for projecting words or images on tall faces in the works. I see it being put to good use for protests and temporal art: non-violent riot porn?
One aspect of laser graffiti potentially comforting to corporations: It costs nothing to remove!
The allure for protesters, artists, and organizers: It travels at the speed of light. But, the projectors look pretty heavy.