All prisons should be legally allowed to partake in the substance they are incarcerated for....

whether it be pot,

whether it be sniffing glue,

slitting their wrists,

raping an unsuspecting pedophile.

once you are proven guilty, all laws should be nullified, within a confined region... prison.

segregate them to their own cliques.

the moderate ones survive, and the truely evil simply act out in appropriate fashion to other thugs.

give the weaker ones access to the gyms,

the stronger ones, the library, if you want to reverse psychology them,

but...

give them their vices and everyone wins.