According to the New York Times, "[t]he Obama administration has taken the extraordinary step of authorizing the targeted killing of an American citizen, the radical Muslim cleric Anwar al-Awlaki, who is believed to have shifted from encouraging attacks on the United States to directly participating in them, intelligence and counterterrorism officials said Tuesday."
The article later goes on to say: "It is extremely rare, if not unprecedented, for an American to be approved for targeted killing, officials said. A former senior legal official in the administration of George W. Bush said he did not know of any American who was approved for targeted killing under the former president." (Emphasis added).
I'm sure Mr. Alwlaki would rather be tortured, but that would be too inhumane.