Perry Fellwock (born c. 1946) is a former National Security Agency (NSA) analyst and whistleblower who revealed the existence of the NSA and its worldwide covert surveillance network in an interview, using the pseudonym Winslow Peck, with magazine in 1971. At the time that Fellwock blew the whistle on ECHELON, the NSA was a little known organization and among the most secretive of the US intelligence agencies. Fellwock revealed that it had a significantly larger budget than the Central Intelligence Agency (CIA). Fellwock was motivated by Daniel Ellsberg's release of the Pentagon Papers.