My dad was a prison officer for quite a few years. I remember his training when i was younger. He came home at weekends and practised the 'holds' he was being taught. It was amazing how much pain he could inflict with a couple of fingers 🙁
He also used to tell me some brilliant stories and some quite horrific ones. It was a good job but it also carried some quite disturbing side effects. My dad had what seemed like parkinsons for a good 12mths before the drugs sorted it and it all stemed from a few incidents including finding a guy hanging in his cell with pictures of his kids taped to his slit wrists,
On the lighter side, i think you will find that the computer games etc are a way of placating the prisoners. If they are busy playing games they are easier to control and therefore do not require as much man power to control. Prisons are seriously understaffed so whatever works is used. It got quite funny as my dad was the best tetris player i have ever seen on a gameboy. He would have spaceships flying all over the place due to massive scores. The lags used to challenege themselves to beat him and it kind of made life pass a bit easier.
As much as i like to think of prisoners sitting in 6ft x 6ft cells with a hole in the floor it just doesnt work in the world we live in. Blame the do gooders, not the prisons.