It's a theory I've heard a lot, the most cohesive version being that the CIA intentionally infiltrated gangs and turned them away from their original purpose of protecting black people/neighborhoods to pushing them into the drug trade and paying them to intentionally cause chaos in poor, black neighborhoods as a measure to prevent anymore black uprisings. What cemented it for me was hearing from various black people working in the system how gangbangers who committed crimes against blacks were given the "revolving door" treatment by the system; i.e. they went in, served minimal time, and were right back out on the streets terrorizing again. How do we have all these gang task forces, but there's no decline in gangbanging? How do black people get football numbers for minor drug possession, but gangmembers are in and out in short time?