This video is from one of the largest prisons in the Phillippines, a maximum-security prison for murderers and rapists. A year ago, violent acts were breaking out all the time between prisoners and also the corrupt guards. Many of the guards were replaced, a new "morning workout" regime was implemented, and now there hasn't been any violence at the prison for over a year. Interesting stuff:
http://www.youtube.com/watch?v=hMnk7lh9M3o