On May 2 2003, local newspapers in Tunbridge Wells, Kent, UK, published a story about mysterious "caped crusader" who appeared to be a real-life superhero. He was wearing a monkey mask and a cape. He helped old ladies to cross the road, taking people home from a pub and saving people from harassing youths.
British media had a field day and even international news organizations got interested. Would-be-superhero was also mentioned onto Have I Got News For You.
The hoax was revealed May 16 2003. All the reports had been manufactured by a small group of hoaxers.