Symbolism will be their downfall. I'm pretty sure the different street gangs are the militia for different factions and bloodlines. The war between the Folk nation and PEOPLE nation collection of gangs has hidden meaning I know. The signs and graffiti is very esoteric, a kind of violent meme magic. MS-13 will fit into this somehow. There are layers and subdivisions like a corporation.
https://en.m.wikipedia.org/wiki/People_Nation