The idea that we allow FOR PROFIT prisons to "employ" prisoners for less than minimum wage while they make money is an embarrassment. This is not justice. This is not "repaying your debt to society". The fact that all criminals get stigmatized and penalized during and well after their incarceration is punishment. The use of them as a labor force to perform tasks to create additional revenue for the prisons is just gross.
And don't get get me started about how this leads to a potential conflict of interest when you allow the prison companies to hire lobbyists who could lobby for harsher sentencing in an effort to create more slaves.