Recent revelations about the Stuxnet and Flame computer attacks show the urgency of threats in the digital universe. Two years ago, the Stuxnet worm, which was designed to attack uranium processing centrifuges, was discovered at an Iranian nuclear plant. Last week, The New York Times reported President Barack Obama approved the operation as part of a secret U.S. and Israeli campaign against Iran begun under the Bush administration. And days ago, we learned of Flame, a cyberespionage mission secretly collecting data in Iran for years. Washington Post investigative reporter Robert O’Harrow has written a series on the fundamental nature of cyberspace. He joins Diane and cybersecurity experts to discuss vulnerabilities and strategies for defense.