True, most of those guys may be posers, but a poser with a loaded gun is a different story. A simple catalyst to escalate a situation is what'll make that poser into a gang banger. I used to play ball on Chalkfarm and Jane with these types and it's tough for some to get out of that environment. True, the posers are there but some of them do want to get out and find a better life usually because of family. Looking at part 2 (5:30 minutes in), there's that guy who is rapping a bit but then gets disturbed by his 'gang friends' who start brandishing their guns to the camera to get their moments of fame for the vid. With all that pressure for them to fit in, it's difficult for one guy to try to become a positive contributing member of society. True, it's hard to see hope when looking at these guys in the video, and you joke around that the youth programs out there are simply not helping, but that's just one piece of the puzzle.
Look at the attitude that's even indicative in this thread. We're not making the situation better by spreading these types of views. Instead of mocking those trying to help the situation, we need to look at ourselves and see what we can do, no matter how small or insignificant it may be. Trust me, I'm guilty of a negative frame of mind myself.
We may not see any change in our lifetime and it will probably even get worse before it gets better, but ... (cue the corny music)... spreading more negativity and pointing blame at others isn't helping.