John Lennon sure was a feisty one. The ex-Beatle protested war, promoted peace and once wrote a song called "I Am the Walrus." No wonder the FBI put him on its watch list before the 1972 Republican National Convention (which the feds erroneously thought he might disrupt), terminated his visa and began deportation proceedings — at the suggestion of Senator Strom Thurmond. During the 1972 presidential election, the FBI monitored Lennon's television appearances and concerts and even followed the activities of Yoko Ono's daughter from a previous marriage. Lennon didn't do anything suspicious, so the FBI closed its investigation a month after Nixon's re-election. After Lennon's murder in 1980, historian Jon Weiner fought a 14-year legal battle to force the FBI to release its Lennon files under the Freedom of Information Act. In the end, he won. The findings are detailed in the 2006 documentary The U.S. vs. John Lennon.