What horrors happen in U.S. prison -- and there are many including rape, extortion, cruelty, lack of compassion or sympathy, and all the worst human traits imaginable (greed, anger, delusion) -- are spurred by the treatment and torture of prisoners by the facility, warden, and fellow inmates. Prisoners run prisons because guards are too cowardly, too underpaid. too poorly staffed to do it themselves.
Nazis, white supremacy gang, Aryan Brotherhood, forced racial segregation
The system is at fault. Guards are trying to survive, prisoners are trying to survive, and prison officials are trying to capitalize on a pre-existing system. One unfairness grows into another. The end product is a toxic system that poisons society. Whatever happens in prison gets to the outside world. Enlightened self-interest teaches us that when we say "we don't care" about prisoners then we must not care too much about the world outside prison.
When people call for harsher and more expensive punishment as the solution, they are contributing to the problem, hardening prisoners and turning them out on a world that did not prevent their severe torture, neglect, and abuse in prison. Many prisoners may be horrible human beings, victims of abuse turned abusers or PTSD-suffering torture victims from the way they are tormented in prison, but they are yet human beings. What we allow to be done to the least of our brothers we do to ourselves. The test of a society is not how it treats its privileged members but how it treats its prisoners.