Earlier quoted context omitted.
thats more an artefact of the fact that most of our prisons were built in the 1800s. 2 in a cell is common. Until the 90s they never had indoor plumbing either, only buckets in the cells. https://en.wikipedia.org/wiki/Slopping_out
The following article is worth a read too on the subject: https://en.wikipedia.org/wiki/1990_Strangeways_Prison_riot I believe it was the squalid conditions that sparked the unrest.
The two most serious ringleaders are both now free, or were in the most recent doc, and are doing fairl well. One is fond of handing out papers with motivational or philosophical thoughts on them and the other now has his own gym.