I read a couple of articles about this and it was the guards making the money. I don't disagree with your sentiment but this sounds more like an abuse of power and torture.
There's so many things wrong here. First of all, to get into prison in China you really don't have to be a criminal. You can be a journalist. Secondly, slave labor is wrong no matter where it is. It's wrong in a US prison, it's wrong in a Chinese prison. Bad conditions in a US prison doesn't make bad conditions right in a…