This is what we get when we run (and fund) previously public institutions as for-profit entities. It's not a small thing, because we create some really twisted incentives when, to fund tax cuts, we strip public funding to a minimum:

Out of California’s years-long litigation over reducing the population of prisons deemed unconstitutionally overcrowded by the U.S. Supreme Court in 2010, another obstacle to addressing the U.S. epidemic of mass incarceration has emerged: The utility of cheap prison labor.

In recent filings, lawyers for the state have resisted court orders that they expand parole programs, reasoning not that releasing inmates early is logistically impossible or would threaten public safety, but instead that prisons won’t have enough minimum security inmates left to perform inmate jobs.

The debate culminated Friday, when a three-judge federal panel ordered California to expand an early parole program. California now has no choice but to broaden a program known as 2-for-1 credits that gives inmates who meet certain milestones the opportunity to have their sentences reduced. But California’s objections raise troubling questions about whether prison labor creates perverse incentives to keep inmates in prison even when they don’t need to be there.