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Marilyn Monroe - Marilyn Monroe was investigated because of her marriage to Arthur Miller, who was a suspected communist.

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R. Kelly - In response to rampant allegations of abuse, R. Kelly is reportedly being investigated by the FBI.

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Princess Diana - Diana's file is pretty brief, but does mention death threats against her, and a planned trip to New York City that was met with protests.

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Ryan Adams - According to reports, the FBI has recently opened an inquiry into Ryan Adams, after reports that he allegedly engaged in sexual activities with a teenager.

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Whitney Houston - The FBI investigated threats to Houston by a fanatic in Vermont, who sent nearly 80 love letters to the singer. There was also an alleged extortion attempt on Houston.

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Jimi Hendrix - The rock icon has a brief file, outlining his criminal history of car thefts. "If he is found innocent of the charge, Canadian Immigration would like to deport him anyway to the US if it can be shown he has prior criminal convictions," one agent wrote.

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Donald Trump - This one shouldn't come as much of a surprise. The FBI has opened an inquiry into Trump, related to his firing of FBI director James B. Comey.

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Walt Disney - Walt Disney actually worked as a FBI informant during the McCarthy era. In return, the Bureau let Disney film 'The Mickey Mouse Club' at the FBI HQ.

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Anna Nicole Smith - Smith was investigated for an alleged murder plot on her late husband's son, who she battled with over inheritance. However, there wasn't enough evidence to charge her.

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Tupac Shakur -

2Pac is one the most famous rappers with an FBI file. He was investigated for death threats that he allegedly received from the Jewish Defense League.

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John Lennon - John Lennon was an active political figure, with strong anti-war messages that resonated with people around the world. The FBI attempted to revoke Lennon's visa.

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James Brown - The Godfather of Soul served a six-year sentence during the late '80s and early '90s for a police car chase that raced through two states. Brown's wife said the local police were unlawful, and the FBI investigated the case. He was released from prison in 1991.

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Grace Kelly - The actress-turned-princess was briefly investigated, after she invited the FBI Director to a gala and banquet.

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Helen Keller - The deaf blind pioneer was heavily investigated for her socialist beliefs, support of birth control, and her co-founding of the American Civil Liberties Union.

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Steve Jobs - President George W. Bush considered Steve Jobs for his Senior Export Council. The FBI did a background check, and reported "several individuals questions Jobs' honesty, stating that [he] will twist the truth and distort reality in order to achieve his goals."

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Liberace - There are over 400 pages on Liberace's file. The pianist was once robbed of his famous jewels, and there were also attempts to extort the pianist too. He was also allegedly involved in illegal horse race betting.

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Michael Jackson - MJ was investigated for controversial allegations of child molestation, between 1993 and 2004. Agents allegedly attempted to get accuser Jordan Chandler to testify in 2004, but he refused.

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Fidel Castro - The FBI did a lot of investigating into the Cuban communist leader. He was theoretically tied to the assassination of JFK, but Castro denied any involvement.

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The Notorious B.I.G. -

Biggie was actually investigated after he died, in December 2002. Funnily enough, an agent misspelled the rapper's name in one report.

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Charlie Chaplin - The FBI file on Charlie Chaplin is over 2,000 pages long. He was a suspected communist sympathizer, and even MI5 helped spy on him. Chaplin was barred from re-entering the US, so the Chaplin crew moved to Switzerland.

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Jim Morrison - The Doors front man was one controversial figure. One report from 1969 said Morrison "pulled out all stops in an effort to provoke chaos among a huge crowd of young people."

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George Steinbrenner - Steinbrenner was the owner of the New York Yankees. The FBI found a lot of dirt on his file, including illegal contributions to Richard Nixon's re-election campaign.

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John Denver - The FBI thought Denver's drug use, and appearance at an anti-war rally, were quite fishy. He was also investigated for death threats that he received.

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Jackie Robinson - Jackie Robinson was more than a baseball player. He was also involved in the Civil Rights movement, which the FBI found to be pretty suspicious.

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Rock Hudson -

The movie star was investigated for allegedly having an affair with a man. "In view of the information that Hudson has homosexual tendencies, interview will be conducted by two mature, experienced Special Agents," read the report.

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Truman Capote - Truman Capote was involved in the activist group, Fair Play for Cuba Committee. The author also circulated rumors about J. Edgar Hoover. "And it got me…about 200 pages in an FBI file," he said.

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Lucille Ball - Lucille Ball had alleged connections to the communist party. However, she was not put on their "security index."

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Bud Abbott and Lou Costello - This hit comedy duo caught the FBI's attention during the 1950s. Abbott was investigated for his collection of pornography, and Costello for interactions with prostitutes.

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The Kingsmen - The Kingsmen scored a hit with 'Louie Louie,' which features hard-to-discern lyrics. The FBI got suspicious, and investigated the song and band.

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Jerry Garcia - Jerry Garcia was the front man of the Grateful Dead, a popular band with a mostly-redacted FBI file. Garcia was investigated for connections to LSD dealers, but nothing conclusive was found.

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