A lot of people have their panties in a wad over the explaination the US Attourney General gave for killing Americans without trial.
In the case of Anwar A, he had renounced his citizenship, and vowed to attack America with every chance he had. He did that on youtube, and in AQAP statements. He almost blew up a jet, while landing in Detroit. He was declared a "terrorist". If you don't do all that, this won't apply to you.
If I had the opportunity, I would have put a bullet in his head myself (no Trial, Judge or Jury). If you have a problem with that, you are not thinking about it. Or you just listen too much to foolish pundits.