Nan Briton had an affair with US president Warren G. Harding in the early 1920s. Harding died of a heart attack in 1923, and Briton tried to sue for child support. She was ridiculed in court. In 2015, Ancestry.com did a DNA analysis on Harding's and Briton's descendants. Nan was telling the truth. u/archfapper

Johnny Lyden when he said on the radio that Jimmy Saville was dodgy. u/Infrared_Herring

Remember when people thought Marie Curie's work was 'too dangerous'? Now we can't imagine medicine and technology without her discoveries. u/eminent_mowing

Barry Marshall (and also Robin Warren his co-researcher). For ever, the cause of peptic ulcers was believed to be stress, spicy food and too much acid production. They believed it was actually of bacterial origin. No-one believed them, they were ridiculed because the belief was that bacteria couldn't survive in the acidic environment of the stomach. Not until Barry took a cocktail of H. pylori bacteria, which caused him to have massive inflammation of the stomach which was found to be colonized with the bacteria, but a course of antibiotics later and it was gone. One Nobel prize later and now the treatment of peptic ulcers is turned on its head and instead of months or years of discomfort it can often be sorted with a week or two course of anti-biotics. u/Djinjja-Ninja

Doctor Clair Cameron Patterson not only discovered the the true age of the Earth with his research in Lead-dating, but during this process he accidentally discovered the dangers of lead contamination. Then he went “wait, we’re putting this stufft in gasoline, cans, paint, etc.” He then began campaigning against lead in everyday products. In particular, he targeted the gasoline industry. You can imagine how that went in the courtroom. He was vilified, excluded, and slandered against but kept pushing for lead to be removed from gasoline. Took decades, but obviously lead was removed from gasoline almost entirely by 1990. u/honeybeebryce

Lindy Chamberlain The 'A Dingo Killed My Baby' lady. She was vilifed, mocked and ridiculed across the world. She then spent three years in prison, before it turned out she was actually telling the truth the whole time, and a dingo did, in fact kill her baby. u/-Some_Random-

The McDonald’s coffee burn incident. Stella Liebeck didn’t want it to be a spectacle, she just wanted her medical bills paid. She wanted her medical bills paid because she had 3rd degree burns on her skin. Coffee shouldn’t be that hot It was ultimately the lawyers and the jury that determined the payout, she had no say in any of it. u/redditor420_69

Sinead O Connor. Was villified when she ripped up a picture of the Pope on SNL for child abuse and criticizing the Catholic Church. Over the following decades we realized how devastatingly right she was about the whole thing. u/Theartofdumbingdown

Joseph Lister One of the first doctors to publicly endorse germ theory and recommend disinfection. At the time surgeons would literally move from an amputation, to an autopsy, to the delivery room using the same tools often without even cleaning the gore from their hands and clothes. When Lister recommended comprehensive disinfection between procedures nearly the whole British medical community laughed at him. He spent years as a pariah gathering data from his own practice until he could finally prove beyond a shadow of a doubt that his methods reduced post-op infection by a staggering rate. Now he's known as "The father of modern surgery." u/SirKedyn

Dominique Moceanu - Dominque came forward in 2008 revealing abuse in USA gymnastics before the 2016 sexual abuse scandal. She was accused of being bitter, lying and seeking attention. She was blacklisted by gymnastics coaches and received threatening e-mails accusing her of basically being a traitor. u/redman9000

Ignaz Semmelweis. The world didn’t know about germs yet, but he saw that way less women were dying from childbirth when midwives attended the births than when doctors did (doctors were coming from autopsies and wrecking women). Ignaz suggested they start washing their hands, and people lost their minds. Doctors ridiculed him and everyone hated him. He had a “nervous breakdown,” was committed to an insane asylum, beaten by the guards, and died from a gangrenous wound as a result of the beating. u/AhemExcuseMeSir

Nicolaus Copernicus, theorized that the planets actually circled the sun instead of the other way around. The church initially accepted heliocentricacy but banned his views in 1600s. u/buckmaster86

John Yudkin was a food scientist who tried hard to push the idea that sugar caused heart disease and obesity amongst other conditions. He suggested a low carb diet for weight loss in 1958. The sugar industry paid scientists like Ansel Keys and D. Mark Hegsted to downplay this connection and suggest that dietary fat caused obesity and heart disease. Massive lobbying helped pro sugar scientists to become advisors to government and officially suggest a low fat diet to prevent heart disease. Taking fat out of food makes it taste bad, so what do they add? More sugar, causing the food to be unhealthier. The demonising of fat lasted well into the 2000's and often still persists to this day. u/Fallenangel152

Patricia Stallings comes to mind. Convicted of poisoning her first child, gave birth in prison (kid got taken away) and the kid also dies. Instead of poisoning it was now found it was a genetic defect that had similar effects as poisoning with antifreeze. u/Wisely_0904

I would say the UN Chief Inspector, Hans Blix, who said in a 2003 report that the UN investigation team had found no evidence of WMD in Iraq. Completely torn apart by the American government, public, and press. And yet… no WMD were ever found in Iraq. u/Strong-Persimmon7071

Monica Lewinsky. She was a 20-y-o White House intern who got taken advantage of. Then the media crucified her for it. u/slappy_mcslapenstein

Alan Turing It crushes my soul just thinking about how much he changed computer science and computation only to have such a horrible end of life. Without him WW2 would have lasted far longer and cost so many more lives. u/IgnatusFordon

John snow. He tried to remove the handle of a water pump in London that was drawing its water downstream from a sewage pipe. People who drew water from the pump caught collera. u/PsychologyStock8353

Richard Jewell - A security guard who found a bomb in a bag at the Olympics. But, for some reason local police told the media that he was a suspect and the press absolutely roasted him for months. Turned out, he was not the bomber. He was in fact a real life hero who possibly saved many lives. But his life was absolutely ruined. The press quickly squashed the story of the real bomber b/c they would have to admit how wrong they were about Richard Jewell first. Years later he couldn't get work because even after the real bomber was caught people still thought he did it. u/Richard Jewell