Prisoners captured in Iraq are not handled with kid gloves and gently placed in a paddy wagon like liberal protestors arrested in Seattle. They are trying to kill Americans when captured and would love nothing better than to kill their captor and escape to fight another day.
While there are some that fit into this category, the vast majority of the prisoners we are dealing with are either people who were arrested on suspicion without any solid evidence, or were arrested for relatively minor crimes such as theft, etc.
Furthermore, even if you look at the worst of the worst, torture is both morally wrong, and technically ineffective. Torturing somebody just gets them to tell you what you want to hear, not what is true. If you were tortured for long enough, you would confess to being a member of Al Qaeda. It's dehumanizing for them and for those who enact the torture.
You may say that they don't deserve better than that, and perhaps you are right. Having said that, it is vitally important for us to be better than them. How can we go around the world demanding that people end human rights abuses when we will readily do the same thing given the chance?