Mines this guy from Monty Python. Really summed up what a dumb job it was. But somehow Australia has turned it into a money-making business. Even the USA adopted the Australian innovation of using the Criminals as 'Free Labour' enterprised.
Now in the USA, Towns ask for these Prisons to be set up. Where the Police issue fines for the drop of a cigarette with can be $90 or a day in Prison. A Day in Prison will also cost the Prisoner another $90 in food and laundry (Daily). If that Prisoner can't pay - it's another day in Prison accumulating cost. That's why many Police in the USA are far more 'revenue rakers' than real police. They're aggressive and forceful, sometimes violent. All aiming for an end of year bonus for their tally.
These Prisoners then work 'lines' of manufacturing products.
China is in an uproar about this because it undermines their $2 a day wage to its people. It hasn't made slaves of them yet. Those that just work to feed themselves are not yet harnessed as a contributer to the Money-Chain.