For centuries, journalists have been willing to go to prison to protect their sources. Back in 1848, New York Herald correspondent John Nugent spent a month in jail for refusing to tell a U.S. Senate committee his source for a leak exposing the secret approval of a treaty with Mexico. In a digital age, however, journalists need more than steadfast conviction to keep themselves and their sources safe. Government intelligence agencies, terrorist groups, and criminal syndicates are using electronic surveillance to learn what journalists are doing and who their sources are. It seems many journalists are not keeping pace.