of information about the NSA-GCHQ [Government Communications Headquarters, a British intelligence agency] relationship, and served as the basis for Bamford's information on Second Party issues [i.e., issues regarding outside agencies with which the NSA had partnered]." The NSA history dryly notes that "GCHQ was not amused" about the disclosure. Bamford also interviewed retired NSA senior officials, including former director Marshall Carter, with whom he talked for a day and a half. None of the discussed subject matter was classified, but, according to the NSA, "it helped Bamford to complete his mosaic." The NSA account also describes how Bamford drove through the NSA parking lot, recording diplomatic license plates and cross-checking them against known lists to determine which countries maintained representatives at Fort Meade. The NSA's historical account summarizes Bamford's work thusly: "James Bamford broke new ground in intelligence agency research, and his techniques were adopted by others seeking to investigate reclusive federal agencies. He did it all within the limits of the law – through attributable interviews, FOIA'ed documents, and meticulous research in public libraries and newspapers. ... He 'wrote the book' on how to put together a comprehensive picture of an organization that wanted no such comprehensive picture." Threatened legal action and document reclassification Before the book's publication, the Reagan administration claimed that unclassified source documents were released to Bamford in error, and threatened him with prosecution if he did not return 250 pages of documents he had obtained through Freedom of Information Act (FOIA) requests. The documents in question related to a 1975-76 DOJ investigation, and described the NSA's widespread illegal monitoring of domestic communication, warrantless surveillance of Americans, and monitoring of commercial cable and telex traffic. Bamford's attorney, believing that they would prevail in court, invited the DOJ to prosecute, but no case was ever brought. In the wake of the dispute, classification rules were revised to allow document reclassification, and the contested documents were reclassified. NSA agents then visited libraries to remove other source documents from circulation. The new rules allowing document reclassification were outlined in Executive Order 12356. Previously, Executive Order 12065, issued by Jimmy Carter in 1978, had prohibited document reclassification. Executive Order 12356, issued by Ronald Reagan in 1982, eliminated the reclassification prohibition and described situations in which documents could be reclassified. Released documents could be reclassified as long as they could be reasonably recovered (meaning that documents available to the public at