Glenn Greenwald is a columnist on civil liberties and US national security issues for the Guardian. A former constitutional lawyer, he has written for Salon and is the author of three books, "How Would a Patriot Act?" a critique of the Bush administration's use of executive power; "A Tragic Legacy," which examines the Bush legacy; and "With Liberty and Justice For Some: How the Law Is Used to Destroy Equality and Protect the Powerful."