 In 1981, while conducting research for a book about John Lennon, Wiener learned of the FBI surveillance, and that there were either 281 or 400 pages of files on the ex-Beatle.Wiener requested the release of the FBI's files on Lennon by citing the Freedom of Information Act.The FBI refused to release two-thirds or 199 pages of the files on the grounds that they contained "national security" information.