Yes, yes, I know he's "shrill". I am too, sometimes. But he's also right 99.99% of the time, and he backs up his assertions (e.g. see the end of Reason #1), and if he's ever not right, he admits it.
Remember that wonderful scene in "Annie Hall" when Woody Allen (as "Alvy Singer") pulls out Marshall McLuhan from the wings and uses him to confront an obnoxious pontificator who is standing in line behind him, then Allen looks at the camera and says, "Boy if only life were like this!" Glenn Greenwald is who I'd like to pull out of the wings.