How prepared is the U.S. to fend off cyber warfare?

“We spent years worrying about the giant cyber-Pearl Harbor,” says David Sanger, author of “The Perfect Weapon: War, Sabotage and Fear in the Cyber Age.” But, he argues, that has blinded us to more subtle uses, in which we are all collateral damage. Sanger joins Judy Woodruff to discuss the threats and realities, how the U.S. wages cyber warfare, and how prepared the U.S. is to stop attacks.