FRONTLINE: United States of Secrets

How did the government come to spy on millions of Americans?  As the national debate over safety vs. privacy rages, FRONTLINE presents a two-part series called "United States of Secrets" (May 13 & 20) that tells the inside story of the U.S. government's massive secret surveillance program - from 9/11, to the Edward Snowden revelations, up through the present.  Filmmaker Jim Gilmore, reporter and co-producer of Part 1, visited with Karl Gehrke about FRONTLINE's "United States of Secrets."  SDPB-TV airs FRONTLINE Tuesday at 8:00 p.m.