In 1976, Sesame Street aired episode 847 with guest star Margaret Hamilton, in her classic persona as the Wicked Witch of the West. It only aired once. The producers received many complaints from parents who said it was too scary for children, and left some of them traumatized. There were also a couple of complaints from Wiccans about showing witches in a bad light. The Children's Television Workshop pulled the episode from circulation, and it was never included in reruns, syndication, or home video. It was never really "lost," (hence the quote marks) as it was archived at the Library of Congress, but most of us have never had the opportunity to see it.
But now you can. This video compiles all the Margaret Hamilton sequences, which total about 15 minutes, and tells the story of how the witch from The Wizard of Oz got into a kerfluffle with Sesame Street residents over her broom. It may seem silly and contrived to us, but it was meant to help preschoolers overcome their fears. I guess it wasn't that successful in its aim. If you like, you can see the full hour here. -via Fark