Glow-in-the-Dark spray paint
Should your petty crimes come to bore you, try executing them with Glow Graffiti, a paint that glows in the dark. The can even has a bright LED next to the nozzle, acting as a kind of primitive meatspace "preview" function,

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Hmm, I think I'd go for a non-LED'd glow paint. Nothing shouts illegal like a guy with flecks of glowing paint on him fleeing from a "I don't care for this administration" tag.
pretty sure the LED also serves to charge with light the paint, so it'll glow.
So wait, is the paint normally invisible? Or is this like that glow in the dark plastic that's a greenish off-white color in the light?
60 bucks?
C'mon, Krylon makes glow in the dark paint.
http://www.krylon.com/products/glowz
Save yourself some dough and buy your own stencils (or make your own), and rig up a uv flashlight to a can of krylon.
Unless you really want the glow canvas and everything in a convenient package. But you could still assemble a similar glow graffiti kit much more economically than that...
http://www.bombingscience.com/montanapaint.htm?category=Alien
about half-way down this page you can get TRUE professional GITD paint for a sixth of the price.
This seems to be blacklight paint rather than true glow in the dark paint.
In fact the Glow Graffiti contains no paint at all. The LED shines out high powered UV light which stimulates the luminescent molecules in the fast acting special light sensitive sheet. The sheet then glows in the places you shined the light and the glow fades after 30 seconds. This means you cannot paint anywhere, only only the special sheet provided.
I hope I've answered peoples questions. Read more at Firebox:
http://www.firebox.com/product/2275/Glow-Graffiti