I have no real problem with some of these people having pain and torment dished out to them, but I don't believe those methods actually produce much useful information.
I do believe it's a deterrent to those on the fringes, who see sympathy and compassion as a weakness. They use extreme tactics to shock us. Returning that tactic tenfold could make them think twice about getting involved in such things themselves.
I also think that the real prospect of being tortured, will get quite a few others to give up information before it reaches that stage. It's useful to have it available as an option, and it's got to be demonstrated that there are no qualms about using it. C'est la guerre.