Is that not the mark energy companies use to show where underground cables run? Arrow pointing the direction of supply? I might be wrong.. but that looks very similar to UK systems for floor marking. Blue for water, Yellow for gas red for Leccy

 

Not gang. For one, gangs don't mark the curb, they're going to throw it up on a wall where it's easily visible. And second, pitchforks point up, and when another gang wants to disrespect they put the forks facing down.

A pitchfork would be Satan, although I'm inclined to say that sideways it's more like a bow and arrow.

So, in conclusion I'd say you're either looking for Satan or Cupid.