Many of these workers are from the prison industrial complex. Pay is non-existent or abysmally low, AFAIK.
Link 1: https://en.wikipedia.org/wiki/Prison%E2%80%93industrial_comp...
Link 2: https://static1.squarespace.com/static/58e127cb1b10e31ed45b2...
>> This report exposes over 3,100 corporations that profit from the devastating mass incarceration of our nation’s marginalized communities
What else do you expect me to do?