Well, no reason not to hunt down and kill people who create computer viruses. If our policy is to violate our own and international laws and commit extrajudicial executions then there would be nothing to stop them except that I doubt there would be public support or support in congress for such a thing. :-) Anyone, including governments can break any law, at any time. It’s a matter of people demanding that the laws be obeyed, enforced and those who break the be held accountable and brought to justice when they are not. Enough Americans either support or don’t care that suspected, alleged terrorists may never, or in the case I believe you are referring to, that of Anwar Awlaki and Samir Khan, in Yemen, didn’t have to go through a legal process that determines their guilt or innocence.