If you can't do the time, don't do the crime." So goes the old saying. Yet conditions in some American facilities are so obscene that they amount to a form of extrajudicial punishment. Doing time is not supposed to include being raped by fellow prisoners or staff, beaten by guards for the slightest provocation, driven mad by long-term solitary confinement, or killed off by medical neglect. These, however, are the fates of thousands of prisoners every year—men, women, and children housed in lockups that give Gitmo and Abu Ghraib a run for their money. The United States boasts the world's highest incarceration rate, with close to 2.3 million people locked away in some 1,800 prisons and 3,000 jails. Most are nasty places by design, aimed at punishment and exclusion rather than rehabilitation; while reliable numbers are hard to come by, at last count 81,622 prisoners were being held in some form of isolation in state and federal prisons. Thousands more are being held...