The Homeland Security Department has issued new guidance to operators of the National Public Warning System, who are distributed throughout the U.S. The guidance is how to protect the system from electromagnetic pulses or EMP, whether caused by sunspots or a nuclear detonation. The guidance was a joint effort of several DHS components. For details, Federal Drive host Tom Temin spoke to Brent Talbot, Science and Technology Directorate program manager Brent Talbot. They first discuss: Why EMP and why now?