A concept I originally had in 1996 about if kids in schools only wore the backpack of their gang. This is some dialog between a backpack gang and their school's principle:
After school.
Principle: So, what are you kids up to, eh?
Gang member #1: What's it to ya!
Principle: I just noticed you have a Jansport on.
Gang member #2: Yeah? So what?
Principle: Well, there were some Eastpaks that broke into the school last night. We caught em'
but we heard that some of you Jansports were there too.
Gang member #1: We don't know nothin' about it!
Gang member #2: Yeah, you got nothin on us.
Principle: I got my eye on you kids...
Gang member #3: Yeah, whatever.