Though the vandalism industry hasn't had a technological innovation since the stencil, this impasse has ended with the introduction of Stuart Wood and Florian Ortkrass' PixelRoller.
Apparently working like a gooey dot-matrix printer on a stick, all the operator must do is stroke the head over the area to be painted, and the roller spurts in accordance with whatever it has been programmed to paint.

"Print anywhere, onto anything," is the marketing hook. "Both indoors and outdoors."

Gizmodo does not condone the misuse of new technology. It just slyly implies, on occasion, that it would be fun to do so.

PixelRoller [random-international.squarespace.com]