There is never a time where torture is acceptable, for revenge, for information, for anything. To do otherwise means you are taking into your own hands the humanity of others, to play god. And that would make you a monster.
You assume that you can easily identify who is guilty and who is not. How do you make sure the person in your hand is guilty in the first place? Do you know that "almost half of 212 Afghan prisoners (in Gitmo) either innocent or forced to fight for Taliban"? [1] How many of them tortured for information they don't have?
There are many countries where people suffer from dictators and oppressing regimes. US (and US citizens) shouldn't give those regimes an excuse for their actions by defending torture for any reason. Those dictators are telling people that they torture for the benefit of the society, to save multiple lives etc. Don't be like them.
Would you agree that even in cases as you describe, those doing the torturing should be prosecuted and punished? I would. If it's as important as you say, then the people doing it should be willing to fall on their swords afterwards.
