Here is an interesting discussion of torture spawned by an email from a person who backs the practice. Their basic argument is that if we do it, it's OK, but it's not OK for the other guys to do it because they are doing it for the wrong reasons.

The commenters to this piece blow holes in the argument like a machine gun. Perhaps this is one of the best:

So the argument is: "We are the good guys, and anything we do is good by definition." Funny, that's the same logic used by the bad guys.

These pro-torture people seem to forget that the terrorists consider us to be evil, therefore justifying their actions. They are fighting for a higher cause, their religion/culture/country. Once you start justifying evil actions by claiming to fight against evil, you have gone off the deep end.