It may sound crazy—especially when you're talking about investigations into flying saucers, nefarious government programs, and ultra-secret, fire-lit gatherings of the world's richest men—but not every conspiracy theory ever uttered is something to scoff at. In fact, many of them have turned out to be completely true. For proof, grab your tin-foil hat and read on, because here we've gathered all of the wildest conspiracy theories that have turned out to be 100 percent rooted in fact.

1 The U.S. Government poisoned alcohol during the prohibition.

Prohibition was introduced in 1920 to control the country's alcohol consumption, but that only resulted in widespread speakeasies and bootlegging, which is the illegal production and distribution of alcohol. The prohibition law proved it wasn't enough to curb drinking habits, so the government took more drastic measures. They decided to poison the country's illegal liquor supply by adding toxins, including highly-lethal methanol, to alcohol in the mid-1920s. In total, it is estimated around 10,000 people died as a result of the government's poisoning.

2 There was a "gaydar" machine developed by the Canadian government.

It seems Canada wasn't always as friendly as it's reputed to be. In the 1950s, the Canadian government hired a university professor to develop a machine that was supposedly able to detect whether or not federal employees were gay, or, to use the derogatory term, "fruits." Called the "Fruit Machine," the apparatus measured pupil dilation in response to same-sex-erotic imagery. As a result of this testing, which went on until the 1960s, many men lost their jobs.

3 A first lady acted as president of the United States.

In 1919, President Woodrow Wilson suffered from a massive stroke, so the first lady, Edith Wilson, began making decisions on his behalf. She prevented news of the seriousness of Wilson's condition from getting out to the public. Instead, all that was said was that he needed rest and would be conducting official business from his bedroom suite. To prevent her husband from resigning, Edith became the de facto president. Historians estimate that she led the country for a year and five months.

4 The U.S. g overnment used dead body parts of infants and children for radioactive testing without permission.

In the 1950s, the United States Atomic Energy Commission started testing tissue samples from newly-deceased children and babies to test radioactive strontium-90, the most severe threat to humans in the event of nuclear fallout. Throughout "Project Sunshine," they gathered more than 1,500 samples throughout Europe and Australia—often without the parents' knowledge or consent—to test the hazardous effects on young human tissue. Years later, a British woman named Jean Prichard reported that she hadn't been allowed to dress her stillborn daughter's body for the funeral in 1975, because (as she later found out) her baby's legs had been removed by British doctors and shipped to the U.S. government. "No one asked me about doing things like that, taking bits and pieces from her," she said.

5 Playing football can cause brain damage.

When a massive organization like the NFL doesn't want a story to out, it will surely do everything it can to keep the evidence hidden. This was indeed the case with linking football to brain damage. In 2002, forensic pathologist Bennet Omalu ruled that professional football player Mike Webster's death was due to football-related brain damage, but the NFL strongly dismissed these claims. However, seven years later, the NFL finally did acknowledge the link between players' concussions and brain damage. This earned Dr. Omalu the American Medical Association's highest honor, and a movie about him called Concussion, starring Will Smith.

6 The CIA secretly gave LSD to unsuspecting individuals to test mind control.

From 1953 to 1964, the CIA secretly dosed individuals with LSD to test the potential effects of mind control. During this practice—called Project MKUltra—thousands of U.S. citizens were given LSD without their knowledge or consent. In 1973, CIA Director Richard Helms ordered the destruction of all records related to MKUltra. So now there is very little evidence that remains, but this immoral research was likely responsible for some resulting deaths.

One of the most notable was that of Frank Olson, a United States Army biochemist and biological weapons researcher who was given LSD without his knowledge or consent in November of 1953.

7 The Gulf of Tonkin attack never happened.

In 1964, President Lyndon Johnson told the public that U.S. ships were attacked by the Vietnamese—known as the Gulf of Tonkin attack—to gain the support of American citizens for the Vietnam War. However, a year later, Johnson admitted there was no attack and was quoted as saying, "For all I know, our Navy was shooting at whales out there." In 2005, official documents from the National Security Agency were released that confirmed that the whole Gulf of Tonkin attack never happened and was fabricated to gain support the war.

8 The U.S. Government was investigating UFOs.

The Advanced Aerospace Threat Identification Program was a government-backed program, which received $22 million between 2008 and 2011. Researchers examined civilians and military personnel who claimed to have seen and interacted with mysterious aerial phenomena for signs of physiological changes. The program also analyzed video and audio recordings of reported UFOs. The efforts and funding for this program were kept hush-hush, and the program was shut down in 2012 due to the lack of findings. Its funds were redistributed to other efforts of higher importance.

9 Twenty-eight black men died of (treatable) syphilis in the name of science.

The Tuskegee Study of Untreated Syphilis in the Negro Male was a Public Health Service study that began in 1932 and recruited 600 poor black men from Alabama as its subjects. The men were told they'd receive treatment for "bad blood"—a colloquialism for syphilis, anemia, and fatigue—but they were misled. Researchers continued the experiment even after penicillin was proven to treat syphilis in 1945. The research finally stopped in 1972, after The New York Times published a story about the study tilted "Syphilis Victims in U.S. Study Went Untreated for 40 Years." Over those four decades, 28 men died of syphilis and 100 more died from related causes.

10 Tobacco companies hid evidence that smoking is deadly.

In the early-1950s, research was starting to show an indisputable link between smoking and lung cancer. However, it wasn't until the late-1990s that tobacco company Philip Morris admitted that smoking could cause cancer. The reason it took so long is that tobacco companies were major lobbyists and generous donors to political campaigns. They were able to buy favor with politicians to help refute the science behind smoking's health risks, claiming it was uncertain. In 2006, a federal judge found tobacco companies guilty of conspiracy, specifically for suppressing research, destroying documents, and manipulating the use of nicotine to increase addiction.

11 The world's richest and most powerful men have a retreat every year .

Each July, some of the wealthiest, most powerful men in the world gather at a campground in California for two weeks of heavy drinking, super-secret talks, and strange rituals. Those that come to this retreat—called Bohemian Grove—have included prominent business leaders, former U.S. presidents, musicians, and oil barons. The participants aren't supposed to conduct business deals there, but there was one exception in 1942 for the Manhattan Project, which led to the creation of the atom bomb. Reportedly, plenty of misbehaving goes on at Bohemian Grove as well.

12 The FBI spied on John Lennon.

Because of his anti-war songs like "Give Peace a Chance," John Lennon was considered a threat under the Nixon administration. In 1971, the FBI put Lennon under surveillance, and the Immigration and Naturalization Service tried to deport him the following year. According to CIA records, they feared he would disrupt the 1972 Republican convention, so the CIA joined with the FBI in gathering intelligence on him.

13 The U.S. Government employed Nazi scientists after World War II.

About 1,600 Nazi scientists were sent to work in the U.S. in 1945 following Germany's defeat in WWII. The program, called Operation Paperclip, was exposed in media outlets, including the New York Times, in 1946. Some of these scientists were involved in Project MKUltra. Wernher von Braun was one of the well-known former Nazi participants in this program, and he was put to work as director of the Development Operations Division of the Army Ballistic Missile Agency. He was involved in the moon landing and developed the Jupiter-C rocket used to launch America's first satellite.

14 The CIA developed a heart attack gun.

In 1975, the CIA revealed a secret weapon that could cause fatal heart attacks. It worked by shooting a small poison dart that could penetrate clothing and left behind nothing but a tiny red dot on the skin. The dart disintegrated on impact, and the target would only feel a small prick, similar to a bug bite. Since the poison denatured quickly, it could not be detected in an autopsy. Therefore, the CIA could carry out assassinations that wouldn't be traced back to them. Many believe the CIA still uses this weapon today.

15 The CIA spied on and controlled the American media.

The CIA project known as Operation Mockingbird spied on members of the Washington press corps, starting in the early 1950s. As part of this operation, they paid journalists to publish CIA propaganda, wiretapped their phones, and monitored their offices to keep tabs on their activities and visitors. The CIA paid student and cultural organizations, as well as magazines to serve as front organizations. The covert operation was finally uncovered in Senate hearings in the mid-1970s.

16 The U.S. Air Force researched using pheromones as a weapon.

This conspiracy theory, which is actually true, gives a whole new meaning to the phrase make love, not war. As the U.S. Defense Department considered various non-lethal chemicals meant to disrupt enemy discipline and morale, one of them was the "Gay Bomb." The research, which was conducted in 1994, was intended to create a bomb that would douse enemy troops in female pheromones. The objective was to make soldiers sexually attracted to one another and negatively impact their effectiveness in combat. However, it was never pursued.

17 The Dalai Lama was a CIA agent.

In the 1960s, the CIA provided the Tibetan Resistance with $1.7 million a year to aid in guerrilla operations against China, which included an annual subsidy of $180,000 to the Dalai Lama. In 1998, the Dalai Lama's administration acknowledged that it did receive these funds from the CIA, but denied reports that the Tibetan leader benefited personally from his subsidiary. Instead, they insisted that it went toward setting up offices in Geneva and New York, as well as some money spent on international lobbying.

18 The U.S. government is watching your internet use.

The government is using its vast resources to track its citizens via their online activities. In fact, according to the Electronic Frontier Foundation (EFF), in 2016, government agencies sent 49,868 requests for user data to Facebook, 27,850 to Google, and 9,076 to Apple. EFF is a major nonprofit organization which defends civil liberties in the digital world and advises the public on internet privacy matters.

19 Contaminated polio vaccines spread a cancer-causing virus.

In 1960, it was discovered that the monkey kidney cells used to make the Salk polio vaccine could cause cancer. Americans were not told about this, and between 1955 and 1963, nearly 100 million children were given this contaminated vaccine. Although the cells were removed from polio vaccines in 1963, scientists around the world continue to identify them in human brain, bone and lung cancers of children and adults.

20 The U.S. government can manipulate the weather.

Operation Popeye was a five-year project in which the U.S. government used a technique called cloud seeding to increase precipitation during the rainy seasons over the North Vietnam Army's moving of vehicles, weapons, and rations across the trail. The general idea of cloud seeding is to send an airborne object, typically an airplane, flying through a cloud while releasing small particulates that give water vapor something to cling to so that it can condense and become rain.

21 The Department of Defense paid for P atriot Acts.

In 2015, Arizona Senators John McCain and Jeff Flake published a report saying that the Department of Defense had spent millions of dollars to have sports organizations put on large shows to display American pride. This included several teams in the NFL, MLB, NBA, and NHL, and others, including the athletic departments of several universities. These shows were meant to drive up military recruiting. In 2016, the NFL agreed to reimburse U.S. taxpayers more than $720,000 of this so-called "paid patriotism" money.

22 The U.S. government planned to commit domestic terrorism and blame Cuba.

Approved by the Pentagon chiefs, the Department of Defense, the Joint Chiefs of Staff, and the CIA, Operation Northwoods was a proposed plan to fabricate acts of terrorism on U.S. soil. If carried out, it would've killed innocent citizens to trick the public into supporting a war against Cuba in the early 1960s. The operation even proposed blowing up a U.S. ship and hijacking planes as a false pretext for war. Luckily, John F. Kennedy, who was the President at the time, put a stop to this planned operation.

23 Nayirah's testimony leading up to the Gulf War was false.

Leading up to the Gulf War, a young girl identified simply as "Nayirah" testified before the Congressional Human Rights Caucus in 1990. She told stories about the treatment of the Kuwaitis by the invading Iraqis, which horrified members of Congress and many Americans. Although many people did die following Iraq's invasion, her testimony was made up. She was actually the daughter of the Kuwaiti ambassador to the U.S., and her testimony was set up as part of a public relations campaign called Citizens for a Free Kuwait, run by a Hill & Knowlton, a public relations firm.

24 What was long-believed to be Hitler's skull was that of a young woman.

For decades, it was believed that Hitler took his own life after World War II ended. Unsurprisingly, there were also many who believed that it was a setup and that he had actually sneaked away. Supposedly, Hitler's skull was in the custody of the Russian government. In 2009, tests were finally performed on the skull. The shocking results revealed that the skull was actually that of a young woman. Ironically, the tests were done to lessen the credibility of the conspiracy theorists who believed he had gone into hiding.

25 Osama bin Laden was hunted down through a fake vaccination program.

The CIA ran a fake vaccination program which eventually led to the capture of Osama bin Laden. They had bin Laden's DNA on file, thanks to his sister who lived in Boston. The goal was to obtain DNA from one of his children who was living at the compound with him and match it to his sister's DNA. Then they could confirm with certainty that bin Laden was indeed inside. A Pakistani doctor went through the city under the guise of the vaccination program and collected DNA samples. They identified bin Laden's DNA through his children, which successfully led to his capture in 2011.