All I can say is, that (1) the French did it a lot in Algeria; and (2) they still lost; and (3) it's wrong. Even if you can explain away (1) & (2) by noting that, well, we're talking about The French here, that doesn't work for (3).
Yeah, the torture of Al Qaeda guys concerns me less than the torture of, I don't know, innocent people -- but it's still wrong, and if the practice goes into general use a lot of innocent people, perhaps named by torture victims who just want to name someone to make it stop, will suffer. And so will the people who do the torturing, and so, indirectly, will the rest of us.
UPDATE: Boy, I was behind the curve on this. I should've checked Radley's main page. He's got posts here and here responding to critics, though not changing his position. I didn't find another post by Oliver, though I notice that he's calling Bush soft on homeland security. Well, certainly by these standards.