I read a book about a gang of soccer hooligans who had gotten arrested in a large number of countries. Some of them thought that Japan was the worse place they'd ever been jailed in as the Japanese guards use all sorts of methods such as underfeeding people and playing inmates off against each other.
I used to live in Fuchu city. It's a lovely place. I had no idea there was a prison there. I had a blast. The only mischief I ever got up to was sneaking into an old abandoned hospital at 1AM with a crew of foreigners from all over the world. We were the most eclectic group from various countries: Czechoslovakia, Finland, England, USA, Canada, Taiwan, Australia and more I'm forgetting. Ahh, memories.
Note, "foreigners" committing crime is a pretty common thing to hear Japanese people say. When they say it, they usually mean people from south east asian countries and they tend to be looked down upon.