One of the many reasons prison should primarily be solitary confinement. Socializing with other prisoners should be very controlled, very brief, and very rare. Think that's 'cruel and unusual'? So is subjecting otherwise straight prisoners to the type of behavior displayed in that video, day after day, week after week, year after year. If anything, the cruelty of solitary would be a deterrent to going to prison, which we need more of in this country.
Solitary prison time would also eliminate the 'training program' prison is notorious for, making soft criminals into hardened ones (no pun intended). And it would eliminate the gang networking, drug use, violence, etc.