Ramzi Yousef, convicted after the 1993 WTC bombing, sues for relief from solitary confinement.

He'll never get out of prison, but — after 15 years — should he get out of solitary confinement? But that's not the question asked in a lawsuit. To win the lawsuit, a court has to deprive government of the choice to treat him like that.

Colin Dayan, a humanities professor at Vanderbilt University who has studied solitary confinement in Arizona, said many prison administrations use isolation without regard to psychological damage to inmates.

"You no longer know what's real," she said. "You can't speak to anyone; you can't touch anyone: your senses no longer have any outlet. You have delusions and become psychotic. Your mind deteriorates."

After his arrest, Yousef — who expected the death penalty — told FBI agents that he had intended "to topple one tower into the other, and cause a total of 250,000 civilian deaths."