For my public speaking class, I did a speech against torture.
Basically, I found what cctmsp13 said to be true - it doesn't work as an information gathering technique. Two of the more interesting anecdotes I found were one case of a U.S. officer's unit capturing an Iraqi. The U.S. officer interrogates the Iraqi because he suspects his unit's gonna be ambushed and wants to know about any guerrillas in the neighborhood. He beats the guy, and threatens the guy. He doesn't budge. The U.S. officer finally puts his gun to the guy's head real dramatic-like, and the Iraqi is convinced he's gonna be executed and is scared to death. The American pulls the trigger...nothing. But the Iraqi starts giving out info. American troops move to arrest the people the officer implicates, and American lives are saved. Right? Wrong. All the names the Iraqi gave were made up just to save his skin, and all the prisoners were released when none were found to have been guilty of anything.
The other was during the Vietnam War, when the South Vietnamese captured an NVA guy. They interrogated him using torture and got nothing. Just defiance. Eventually he was turned over to the Americans, who used much less coercive, even friendly, treatment of the prisoner, and he gave them tons of information and even decided to fight alongside the Americans.
Torture just doesn't work. It's rare to get useful information. Either the prisoner turns defiant and welcomes death, or they'll just lie and lie, saying whatever it takes to make it stop. Maybe the poster should say "If wiring a couple hundred Iraqi prisoner's scrotums MIGHT save one American life..." instead. And in that case, anybody who'd support that is flat out a disgusting human being.