IT'S NOT PUNISHMENT, JUST ENCOURAGEMENT:

Scalia accepts infliction of pain to get key information (The Associated Press, February 13, 2008)

[Justice] Scalia, visiting London during a break in the court's calendar, referred generally to those methods as "so-called torture," and said practices prohibited by the Constitution in the context of the criminal justice system -- including indefinite detention -- are readily allowed in other situations, such as when a witness refuses to answer a question in court.

"I suppose it's the same thing about so-called torture," he said. "Is it really so easy to determine that smacking someone in the face to find out where he has hidden the bomb that is about to blow up Los Angeles is prohibited by the Constitution?

"Is it obvious, that what can't be done for punishment can't be done to exact information that is crucial to the society? I think it's not at all an easy question, to tell you the truth."