As Vietnam War protests grew, the U.S. National Security Agency (NSA) tapped the overseas communications of prominent American critics of the war -- including a pair of sitting U.S. senators. That's according to a recently declassified NSA history, which called the effort "disreputable if not outright illegal."

For years the names of the surveillance targets were kept secret. But after a decision by the Interagency Security Classification Appeals Panel, in response to an appeal by the National Security Archive at George Washington University, the NSA has declassified them for the first time. The names of the NSA's targets are eye-popping. Civil rights leaders Martin Luther King and Whitney Young were on the watch list, as were the boxer Muhammad Ali, New York Times journalist Tom Wicker, and veteran Washington Post humor columnist Art Buchwald. But perhaps the most startling fact in the declassified document is that the NSA was tasked with monitoring the overseas telephone calls and cable traffic of two prominent members of Congress, Sen. Frank Church (D-Idaho) and Sen. Howard Baker (R-Tenn.). As shocking as the recent revelations about the NSA's domestic eavesdropping have been, there has been no evidence so far of today's signal intelligence corps taking a step like this, to monitor the White House's political enemies....