OP Fucked up the title:

‘Books keep our minds free’: US prisons ban reading materials at alarming pace

Kind of misleading article. There’s no censorship at work here, because that involves prohibiting viewpoints based on content. Anyone that knows someone that works at a prison know those guys don’t read. They’re not funding libraries because they’re for-profit businesses and why spend on an unnecessary expense for people that can’t complain. If they could avoid spending on food and cleaning they would (and do). The contraband thing is standard and probably because the people working their are stealing anything of value mailed to an inmate, or just to flex their power. I’d be more shocked if they had any idea what was in these books they’re accused of censoring than if they were censoring.