Law professor Jack Goldsmith's review of Michael Kinsley's review of Glenn Greenwald's book is well worth a read. http://www.lawfareblog.com/2014/05/why-kinsley-is-wrong-about-the-connection-between-democracy-and-publication-of-national-security-secrets/
"One problem with Kinsley’s conclusion is that it pushes to government absolutism on secrets in the name of Democracy, and yet the People cannot judge its government’s secret actions. Yes, the People have approved through law a system of checks and balances behind the wall of secrecy, but that does not suffice. Many leaks over the past decade – on interrogations, drones, and surveillance, for example – have led the People to alter the course of government action. If the government had the final say, these and dozens of other reforms and corrections never could have occurred. Especially in an era of endless war, the government should not decide as a final matter what the People know.
So leaks of secrets will occur, and they are sometimes normatively appropriate. But of course this necessary check on government leads to all sorts of problems. For secrecy too is sometimes necessary and appropriate, and journalists sometimes, perhaps often, publish secrets that cause enormous harms that outweigh any conceivable benefit from the perspective of democratic governance."