You do have a point. I think the lobbying to increase the number of slaves makes it more exploitative, but the line really is at the point where working in pris

You do have a point. I think the lobbying to increase the number of slaves makes it more exploitative, but the line really is at the point where working in prison is required. And actually, there's an even more precise and similarly distasteful word that describes it perfectly: "forced labor camp". Some might object that the term invokes a comparison to the forced labor camps in countries with much worse human rights situations than our own. But that seems a lot like saying that house slaves didn't count as "real" slaves, because their lot was much better than those forced to work in mines.