Well, occasionally people who abuse people in private prisons get put to justice. This is generally made difficult by ... of course ... the public part of the system (here we have involved: judges, a supreme court justice, the public prosecutor and the governor. It's about as public as it gets, the private prison was just a way to get the money out. The corrupt parts were very thoroughly publicly funded. And of course the vast majority of the corruption (ie. the public prosecutor, who was the real central part of it) got of without any consequences)
The prison with the worst reputation (deserved or not) is still Riker's island. And it's very much public. It has had it's share of corruption cases, but nobody was ever punished.
And since people seem to really care about this part: Riker's island is very, very much violating the law constantly about the conditions. Everything from medical care, maximum occupancy, to temperatures (both in summer and in winter). The law is very clear: that means no more prisoners there until these issues are fixed. But that would cost money. So, of course, everybody in the justice system cooperates to violate the law. That, by itself, regardless of anything else, is a crime.
The prison with the worst reputation (deserved or not) is still Riker's island. And it's very much public. It has had it's share of corruption cases, but nobody was ever punished.
https://www.youtube.com/watch?v=9RQJq1ca7jM
And since people seem to really care about this part: Riker's island is very, very much violating the law constantly about the conditions. Everything from medical care, maximum occupancy, to temperatures (both in summer and in winter). The law is very clear: that means no more prisoners there until these issues are fixed. But that would cost money. So, of course, everybody in the justice system cooperates to violate the law. That, by itself, regardless of anything else, is a crime.