Supermax prisons, as described in Going Up the River: Travels in a Prison Nation by Joseph T. Hallinan:
Inmates are locked in solitary-confinement cells twenty-three hours a day for years on end and given nothing -- not even work -- to occupy their hours. Most supermaxes are designed to be so devoid of stimulation that inmates are, quite intentionally, driven to the brink of mental collapse. At one supermax in California, more than two hundred inmates, or about one of every nineteen, were diagnosed as psychotic. Doctors who visited the prison reported finding "bug-eyed" inmates who were incoherent, heard voices, or had hallucinations. One wrote a suicide note in his own blood.
That's how Moussaoui's going to be living. To any right-wing whiner who thinks he got off easy, I say: I'd like to see you try living this way for six months, never mind for life.