25 Of The Greatest Conspiracy Theories In History

Jesse Ventura's not the only suspicious one: From JFK to Princess Di, check out our collection of conspiracy theories, far and wide.

Princess Diana Death: One of the biggest recent conspiracy theories got new momentum this month. As RadarOnline.com has reported, Scotland Yard has revealed it is investigating a claim that the car crash that killed Princess Diana and her boyfriend Dodi Fayed in Paris in August 1997 was actually arranged by British Special Forces operatives. The new investigation follows author Alan Power’s allegations that a decision was made to kill Diana to stop her from revealing embarrassing information about her former husband, Prince Charles. Both French and British authorities found the deaths to be the result of an accident.

President John F. Kennedy Death: The assassination of President Kennedy while he rode in a motorcade in Dallas, Texas, on Nov. 22, 1963, has sparked countless conspiracy theories over the years. Although Lee Harvey Oswald was arrested for Kennedy's murder, he was soon shot and killed by Jack Ruby. Many people don’t believe Oswald was responsible for Kennedy's murder—or he didn’t act alone, working for the Mafia, the FBI, or the KGB. Because of eyewitness confusion, the idea that there might have been more than one gunman in different locations has been popular, even though modern TV recreations of the crime scene, using scientific techniques, affirmed the Warren Commission’s finding that Oswald acted alone, firing from the Texas School Book Depository.

AIDS Origins: Theorists have insisted that the deadly HIV/AIDS virus was created by the CIA to wipe out homosexuals and African Americans. Former South African President Thabo Mbeki, for one, disputed scientific claims that the virus originated in Africa -- and accused the U.S. government of manufacturing the disease in military labs. Another theory goes that gay men were deliberately injected with the virus during 1978 hepatitis-B experiments in America. Kanye West has even jumped on this conspiracy bandwagon! In his 2005 acceptance speech for winning the Millions More Movement Image Award, Kanye said that the government was infecting people of African origin to weaken them.

Flight 800: In 1996, TWA Flight 800 crashed off the coast of Long Island, killing all 230 people on board. The National Transportation Safety Board said that the crash was caused by a gas tank explosion. But many eyewitnesses claimed they’d seen a streak of fire heading towards the plane before it crashed. Some believe the aircraft was hit by a missile from a terrorist or a U.S. Navy vessel, and a cover up ensued. The documentary TWA Flight 800, which aired this summer on EPIX, contended there was proof of an external detonation, but that’s been denied.

Moon Landing: On July 20, 1969, awestruck Americans watched on TV as astronaut Neil Armstrong become the first man to walk on the moon. According to conspiracy theorists, however, the moon landing was a hoax concocted by NASA and other organizations and a soundstage was used to fake the whole thing. These theorists believe there was not enough technology to accomplish the moon landing at that time—but the United States desperately needed the prestige of the event. NASA has dismissed the theories as ridiculous.

Roswell, New Mexico: On July 8, 1947, the Roswell Army Air Field caused a sensation by issuing a press release, which stated that they had recovered a crashed "flying disc" from a ranch near Roswell, New Mexico. Although the military later announced it was actually a weather balloon, many still believed a flying saucer had landed, and years later, a former mortician announced that alien autopsies had also been conducted at the Roswell base. In 1995, the officials investigated the incident, and announced that the "weather balloon" they had recovered was actually a high-altitude balloon that was intended to detect bomb waves from atomic bomb and ballistic missile tests. They also debunked the supposed alien autopsies, saying that the bodies were actually those of dead soldiers and test dummies.

9/11: Were the Sept. 11, 2001 terrorist attacks on the United States allowed to happen—or planned by the U.S. government? Most people accept that four commercial jets were taken over by terrorists that day, with two crashing into the Twin Towers of New York’s World Trade Center. While Al-Qaeda terrorists claimed responsibility for the attacks, which killed almost 3,000 people, since then, conspiracy theorists have claimed that either members of the U.S. government had been warned about the attacks and allowed them to happen, or, some members of the government actually were responsible for the attacks, using remote-control planes and demolition materials. According to the theorists, the attacks were used to justify wars in Iraq and Afghanistan. Rosie O’Donnell has openly discussed her 9/11 doubts, saying on The View in 2007 that the way the World Trade Center buildings fell “defies physics.” Charlie Sheen has said 9/11 “raises a lot of questions.”

Sandy Hook: As RadarOnline.com has reported, a Florida Atlantic University communications professor made shocking claims that the 2012 Sandy Hook school shooting in Newtown, Conn. didn’t really happen and that it was just President Barack Obama’sadministration’s effort to sway public opinion in favor of gun control! James Tracy, already known for his outlandish conspiracy theories, established a chronological timeline of the massacre in Newtown on his blog, memoryholeblog.com, claiming to find holes in it, and also gave interviews pointing to a political agenda surrounding the shooting.

Barack Obama’s Birthplace: Many have raised questions about Barack Obama’s presidential legitimacy, claiming that he wasn’t actually born in the United States. The theories hold that either his birth certificate was faked or that he holds dual citizenship and this disqualifies him as President. Most “birthers” contend that Obama was born in his father’s country, Africa. Although Obama’s campaign released his Hawaiian birth certificate, that has never satisfied people like Donald Trump! Just this month, the mogul said on ABC’s This Week, “Was there a birth certificate?...Some people say that was not his birth certificate.”

The Holocaust: Despite the historical facts about the mass murder of six million Jews during World War II, there are a number of deniers who claim that the Holocaust is a hoax. According to the theorists, there was no systematic attempt by the Nazis to exterminate the Jews and the Holocaust claim arose out of a deliberate Jewish conspiracy to advance the interest of Jews and to justify the creation of Israel. Incredibly, people have argued that: the figure of six million Jewish deaths is an exaggeration; deaths in the concentration camps were the results of disease or starvation but not policy; and that the famous diary of Anne Frank is a forgery.

Mars: Is there life on Mars? Many believe that’s true, and photographs taken in 1976 prove it! In fact, comedian Richard Belzer, in his book UFOs, JFK, and Elvis: Conspiracies You Don't Have to be Crazy to Believe, Belzer asserts that there are photographs taken by the Viking orbiter of "an enormous, sculpted face staring up from the Martian surface.” Belzer contends that the photos also show a sphinx Mars: Is there life on Mars? Many believe that’s true, and photographs taken in 1976 prove it! In fact, comedian Richard Belzer, in his book UFOs, JFK, and Elvis: Conspiracies You Don't Have to be Crazy to Believe, Belzer asserts that there are photographs taken by the Viking orbiter of "an enormous, sculpted face staring up from the Martian surface.” Belzer contends that the photos also show a sphinx and a five-sided pyramid, which could be proof that our own pyramids were built by Martians.and a five-sided pyramid, which could be proof that our own pyramids were built by Martians.

Katrina: The slow response time following the 2005 Hurricane Katrina caused a lot of people to claim that the disaster was deliberately exploited by President George W. Bush. One theory is that the Army Corps of Engineers breached the levees to flood poor black neighborhoods, in order to spare the richer white neighborhoods. Another theory is that Halliburton breached the levees, in order to profit off disaster clean-up. Director Spike Lee has accused the U.S. government of flooding of NOLA's Lower 9th Ward. "I wouldn't put anything past the U.S. government when it comes to people of color," he told Reuters. "There is too much history."

Psychiatry: Scientology founder L. Ron Hubbard came to believe that psychiatrists were behind a worldwide conspiracy to attack the religion and create a "world government" run by psychiatrists on behalf of the USSR. In recent years, Scientologists have also claimed that psychiatry is an unsafe medical practice adopted from Nazi concentration camps. Top Scientologist Tom Cruise famously dissed actress Brooke Shields on the Today show for her use of anti-depressant medication.

Vaccines: According to Robert F. Kennedy, Jr. and others, a vaccine preservative causes autism when injected into children. The politician believes government epidemiologists and other scientists, conspiring with the vaccine industry, have covered up data and lied about vaccine ingredients to hide the problem. And new View hostess Jenny McCarthy, who has an autistic son, has said, "Mothers of children who have seen autism have been saying for years... 'We vaccinated our baby and something happened.' " But many staunchly debunk that idea.

Coke: When the Coca-Cola Company introduced New Coke in 1985, the public hated it, forcing beverage bigwigs to bring back the original Coke. But what looked like a simple business bust evolved into a conspiracy theory as many insist the company intentionally changed to an inferior formula with New Coke in order to create demand for their classic product, later reintroducing it to make more money. But Coke execs have denied it, saying New Coke just didn’t catch on.

Chess Game: There is a theory that the famous 1997 chess match in which a computer finally beat a human (Russian champ Garry Kasparov) was a fraud. Theorists say IBM cheated with its Deep Blue computer in order to get publicity. In a 2003 documentary, Kasparov himself argued IBM had secretly used humans to help the computer win--but the company said the only human intervention occurred between games and Deep Blue won fair and square.

The Beatles: Conspiracy-minded Beatle fans assert that Paul McCartney’s band mates secretly covered up his death after the rocker died in a 1966 car accident. According to the theory, John Lennon, George Harrison, and Ringo Starr hired someone who looked like Paul to be his substitute and continue the success of the band -- but guilt eventually caused them to hide clues that Paul was dead in their albums. Lennon’s song A Day in the Life, for example, had the lyrics, "He blew his mind out in a car" and a picture of Paul on the cover of Abbey Road walking barefoot allegedly proved he had died. However, Paul, who recently turned 71, has laughed about the rumors.

The Shroud of Turin: The alleged burial cloth of Christ, known as the Shroud of Turin, has always caused a commotion with some doubting its authenticity and others saying it showed Jesus was alive AFTER the crucifixion. And the 1994 book The Jesus Conspiracy claimed that the Vatican interfered with the carbon dating of the shroud to make it look phony, because Christ surviving the crucifixion would wreck the theology of the church. But the Vatican has denied it.

Digital Television: According to some theorists, Big Brother is truly watching you—because miniature cameras and microphones have been built into digital TVs to spy on people. Another theory related to this is that mind control technology has been hidden in the digital sets to not only use mind control but to plant subliminal advertising.

Water Fluoridation: While all major health groups support public water fluoridation to reduce tooth decay, conspiracy theories about the move abound. Those claims include: that fluoridation is part of a New World Order plot to take over the world, fluoridation was designed by the military-industrial complex to protect the U.S. atom bomb program from litigation, and fluoridation is intended to poison the public, lowering mental abilities. According to theorists, fluoridation secretly benefits corporations or governments.

Pearl Harbor: A persistent historical theory holds that President Franklin Roosevelt knew in advance about the Japanese attack on Pearl Harbor in Hawaii in December 1941. He supposedly needed the bellicose act to propel the U.S. into the war--because the American public and Congress were overwhelmingly against joining the conflict. Theorists say that the U.S. was warned by other countries about the impending attack and America had already broken all the important Japanese codes. But Roosevelt allegedly covered up the fact he knew all along. Historians have largely dismissed this claim.

NBA: According to the “frozen envelope theory,” the NBA rigged its 1985 draft lottery so the best player, Patrick Ewing, would wind up on the New York Knicks and revive the team. Theorists believe that the Knicks' envelope was placed in a freezer so that when NBA commissioner David Stern reached into a bowl containing the envelopes of all the participating teams, he would choose the cold one! NBA officials denied the bizarre charge.

Global Warming: Sorry, Al Gore! Some climate change doubters believe that the idea of man-made global warming is a conspiracy intended to give us higher taxes, control our lifestyle and lead to more authoritarian government. The anti-global warming crowd has argued there’s actually been a levelling off in the rise in temperature since 1998.

Shakespeare: To be, or not to be? The question is, who really was the English language's greatest writer? Theorists contend it couldn’t have been the businessman and minor actor Shakespeare, who was surely too dumb to write the plays – but passed them off as his own. The anti-Shakespeare crowd says Francis Bacon, Ben Jonson, Sir Walter Raleigh or Christopher Marlowe could have written the works. Because very little biographical information exists about Shakespeare, this idea continues to be debated.

Hockey: A major sports conspiracy theory holds that the Soviets threw the famous game against America’s famed “Miracle on Ice” hockey team in the 1980 Olympics. During the Winter Games, the story goes, the USSR heard that President Jimmy Carter was considering an American boycott of the 1980 Summer Games in Moscow. Allegedly concerned that a U.S. boycott would wreck the Moscow games, the Russian hockey team was ordered to lose their game against the U.S., hoping that a stunning American victory would convince Carter to allow the summer team to compete. Sports historians, however, have poo-pooed the notion the Russian athletes would ever have deliberately lost a game.