Al-Awlaki was murdered on suspicion that there was an imminent threat to US persons. No warrant obtained. Al-Awlaki's son was murdered, again without warrant, because of complicated reasons that boil down to his last name being Awlaki.
Any of those videos by themselves would be enough for you to be included on the kill list, and executed. No court would have to be involved. You could also be executed by mistake, like Awlaki's son, or many Yemeni children that were so. Or being kidnapped in Italy by CIA agents into a plane, and imprisoned without trial. Or you could be an Al-Jazeera journalist, being arrested by the Pakistani army, then imprisoned in Guantanamo Bay for six years without any crime charged against you, like Sami al-Hajj. It's all fair game.
Oh, don't forget that you could lose your job as a politician because you hired a prostitute, and the Mormon CIA doesn't like that. Definitely fair.