Richard Posner and Geoffrey Stone discussed their books with David Hiller and responded to audience members' questions. Richard Posner is the author of Uncertain Shield: The U.S. Intelligence System in the Throes of Reform, published by Rowman and Littlefield Publishers. In this follow-up to Preventing Surprise Attacks, Judge Posner detailed the latest changes in national security and warns against an overly centralized intelligence system. Geoffrey Stone is the author of Perilous Times: Free Speech in Wartime from the Sedition Act of 1798 to the War on Terrorism, published by W. W. Norton and Company. In the book Mr. Stone analyzed the relationship between national security and First Amendment rights during wartime.