Complex sentence: In 1983, Wiener sued the FBI under the Freedom of Information Act for their files on John Lennon, which document the Bureau's role in the Nixon Administration attempt to deport Lennon in 1972 to stop his anti-war campaign before the Nixon re-election campaign.
Split into simpler sentences: In 1983, Wiener sued the FBI under the Freedom of Information Act for their files on John Lennon. He states they document the Bureau's role in the Nixon Administration attempt to deport Lennon in 1972 to stop his anti-war campaign before the Nixon re-election campaign.