Helen Duncan was sort of the Long Island Medium of her day. She traveled the UK holding seances, offering her patrons closure, and probably only swiping the occasional pocket watch. During one such divination in April of 1944, she told a pair of worried parents that two British battleships -- including their son's, the HMS Barham -- had sunk. Military authorities, fearing a leak of state secrets in such close proximity to the Normandy landings and completely oblivious to the fact that Duncan could have garnered the information from a strikingly un-supernatural source known as "the newspaper," picked her up and charged her with conspiracy, fraud, and, to top it all off, violation of the Witchcraft Act of 1735. Only the black magic charge stuck, and Duncan was sentenced to nine months in prison. For black magic. In 1944.
Now, we'd be misleading you if we implied that people didn't find this utterly ridiculous even at the time. Winston Churchill himself visited Duncan in prison and, in a powerful act of British solidarity, declared the entire affair "tomfoolery." Still, Duncan served out her time, and her conviction stands to this day, despite the fact that Churchill repealed the sorely outdated act under which she was convicted in 1951.