Waterboarding...

[jake]

If I captured several "terrorists" or just plain enemy combantants. I put them all in the same room and line them up. Ask one a question. He doesn't answer, blow his head off. Go down the line.

The problem with that idea is that if the second guy in line doesn't know the answer to your question, but doesn't want to die, he will tell you what he thinks you want to hear. And as YOU don't know the answer to your question either, you might just believe it.