You are stating private jails don't control the government. You're right, the opposite is true: government officials control private jails, which means delivering inmates and redirecting profits ...
Last big scandal about large scale wrongful imprisonment - of children, no less - the people profiting from this were:
1) Directly profiting
* the District Attorney
* 2 judges
* the director of ... of the Juvenile Probation Office
* the brother of the District Attorney, who ran the prison
2) Involved, capable of stopping the abuse, not proven to have personally profited, yet they cooperated:
* the district attorney
* a supreme court lawyer
* a supreme court justice personally
* the whole Pennsylvania supreme court
* the governor of Pennsylvania
* Pennsylvania's Judicial Conduct Board
* the FBI
3) the only parties the justice system considered guilty
* the brother of the District Attorney, who ran the prison. Note: he's still in business. The SAME business. He was convicted for a small amount, because he lied about paying off judges. He, and his brother the district attorney, are of course completely innocent of plotting for a decade to wrongfully imprison children, for profit.
The scheme continued for 7 YEARS after complaints about corruption were filed.
The profit has not been paid back.
* the lowest level judges
https://en.wikipedia.org/wiki/Kids_for_cash_scandal
As always, we come to the same point as always: people claiming the government can be trusted, because of $reason. Separation of powers, because of the law, because ... You forget the government is a system made up of people. Guarantees, laws, contracts, achieve nothing the quality of people in government doesn't achieve. And we all know that quality is lacking somewhat. Also, this cannot be fixed by better laws, better such guarantees, any of that ...