Just to set the stage as to how large the prison population is in the United States: our prison population is the highest in the world; one out of 100 US residents are in prison. This number has grown dramatically since 1990, due to tighter crime laws and longer sentences. According to the American Civil Liberties Union (ACLU), ‘Between 1970 and 2005, the number of people incarcerated in the United States grew by 700 percent. Today, the United States incarcerates approximately 2.3 million people.’

The private prison population has also been exploding. From the ACLU:

Even compared to this breathtaking rate of overall growth in incarceration, the rate of expansion of for-profit imprisonment far outpaced the field, accounting for a disproportionate increase in the number of people locked up. In 1980, private adult prisons did not exist on American soil, but by 1990 private prison companies had established a firm foothold, boasting 67 for-profit facilities and an average daily population of roughly 7,000 prisoners. During the next twenty years (from 1990 to 2009) the number of people incarcerated in private prisons increased by more than 1600%, growing from approximately 7,000 to approximately 129,000 inmates.

The largest private prison company, […]