>I actually know people that had some business inside prison in EU country
ok but there does seem to be some perception in the world that the prisons in the U.S might be slightly lacking in some of the human rights protections found in EU prisons - you are aware of this concern right?
>Since prison work is voluntary, there is not much space for exploitation.
Again, speaking about the U.S, and I know that in Utah prison work is not exactly voluntary in that the parole board has power to release or make stay to your maximum sentence - so in Utah you go in with a possible 1-15 years, if the parole board wants to let you go in 1 year you can go (but of course be on parole and get pulled back in again later if considered necessary), so how do you get the parole board to consider letting you out in 1 year instead of 15 - well you get a job and work every day and show them that you are good. Other tools are of course used for compliance and to make people work.
This is of course one state and things vary by state the American system, but there are plenty of states considered much worse than Utah for prisoner exploitation so in conclusion, I know things are great in the EU is not going to calm any worries in a discussion about the US.