Which part, the gang sign or the ID cards?
Well, I would think that the gang sign is the easy part. Super informal, we can whip that out anywhere.
With the ID card, there might be issues. With as many members as we have, it would cost a pretty penny to make all of those. And of course, banned members will have fake ones made so that they could get into meets and stuff, thus creating a black market. All goes downhill from there...
Do not go there. Mohandas Ghandi wrote several articles praising Adolf Hitler.
Once again I think you all need to check out that film "The Wave" (Der Weill) to see how quickly cults of inclusion can turn sour.