What they do,they isolate gang members, or dangerous individuals, in separate prisons. Then they start to feed on themselves. My 'little brother' got out in 2011, he has been locked down since 1999. The gangsters start politicking, and, next thing you know, your cellie stabs you. They make monsters, and the whole system is run by gang members.
For example, the number of gang murders in LA, among Hispanic gang members has plummeted since the early 90s. Because the Mexican Mafia put a stop to drive bys and other things that make 'La Raza' look bad. My uncle told me that he saw at least 200 stabbings in prison to enforce this. Another example...My 'little brother' is an esteemed gang member. A decade ago he was in county with a kid that had an 18 month term; somebody talked bad about my brother and this kid cut his throat and, instead of going home, caught another 5 years.
I know a guy that was never a gang member, just a solid stand up individual; a bully in his own right, he liked to beat up gang members. So they told on him, got him validated and put in the hole with them, so they could kill him. He's my age, no young man, and he had two choices; sacrifice his principles and lock up, or get killed.