Pros: I always lol at signage jokes, so good job at getting something flammable in your screencap. Though if you can manage a raging, fiery Tank in the future without dying whilst hitting "F5"... ;)
The text part of the spray looks very good.
EDIT: Also doubles as a pun on the Smokers, I'm an idiot for not seeing that sooner. XD
Cons: Some white artifacts in the center of the spray - you can mitigate this with a higher-res source pic.
Also, I think you can push your style further to look weathered.
Improvements: The blur is a good start for a worn look, but also consider your alpha mask -- get a splotchy brush and paint in various shades of grey for different levels of opacity/transparency. You can use the gradient tool to make it look like certain areas of the spray have more sun damage than others. And finally, if you make all the white areas in your spray a light grey, the entire thing will be semi-transparent so that the wall texture peeks through.
Don't go too crazy - but a few more subtle wear effects can push the style of this to the next level.
Notes: I'd expect to see this kind of notice as a sign rather than painted, so that impacted my style rating a bit. Oh, well. Now go find a Tank or Smoker to piss off!