And what, apart from legal approval, is morally or materially different about forcing a prisoner to work and forcing a free citizen to work?
What, apart from legal approval is morally or materially different from performing capital punishment on convicted murderers and performing capital punishment on a free citizen?
The point is there is a spectrum/grey line.
I find it pretty disturbing that you can't tell the difference. That's a rather serious moral failing on your part.
Sweet! Value judgments on the internet!
Prisoners have been one of the most common types of slaves in history. And one of the few explicitly tolerated as such in places that like to claim they've abolished slavery. [0]