Initial news reports indicate that the identification of the compound at Abbottabad resulted from tracking bin Laden's most trusted courier. The identity of that courier was obtained after interrogation of a detainee at Guantanamo produced the courier's nickname. We don't know (and will likely never know) what sorts of interrogation techniques were used to obtain that information from the detainee but it is probably safe to assume the techniques were not pleasant. ...
One of the main arguments against torture has always been that it doesn't work. Writing at the Daily Beast in April 2009, for example, a senior military interrogator complained that torture failed to produce information to find Osama bin Laden. But here we are, two years later, and interrogation (enhanced or otherwise) of a detainee unlocked the door that led yesterday to the raid at Abbottabad.
I don't care whether torture works or not. As a lawyer, I find it significant that the Anglo-American tradition, according to the great English jurist William Blackstone, includes a "prohibition not only of killing and maiming, but also of torturing (to which our laws are strangers)." As a Catholic, I find it significant that Vatican II’s Pastoral Constitution on the Church in the Modern World explicitly disapproved of mutilation and torture as offensive to human dignity. In my view, even if torture works, we ought to abstain from torture because a prohibition of torture is part of the moral and legal heritage we are fighting to defend.
As for reports that Osama bin Laden was killed in a fire fight, I have no problem with that. Killing of an enemy leader in combat during wartime strikes me as morally licit, as I explained in this post. If it was true that bin Laden was assassinated -- "done in by a double tap -- boom, boom -- to the left side of his face" -- while defenseless and at a time when he could have been captured, however, that strikes me as morally illicit for the reasons I discussed in this post.