There should never be a profit motivation to put Americans behind bars. It's immoral and inhumane. Profit in incarceration corrupts and usurps the power and accountability of the justice system.
The privatization of prisons and jails has created a powerful "prison lobby" in this country, which is motivated to jail more Americans in worse conditions and thereby make more profit. When private prisons commit crimes, no one is held criminally responsible because they're corporations and they control the system in the first place.
The U.S. has the highest incarceration rate in the world, (followed by Russia) and the state of our prisons has deteriorated to the point there are violations of the 8th Amendment protections against cruel and unusual punishment, especially for nonviolent crimes.