In the age of the DVR nothing gets lost. But back in the 70s it was possible for something to air once, never be seen again and slip away into urban legend. Such is the case of a 1976 episode of Sesame Street, featuring Margaret Hamilton reprising her role as the Wicked Witch of the West from The Wizard of Oz. The episode played once and was promptly disappeared, never to be seen again.
You might think it was copyright that kept the episode out of reruns, but the truth is much more delightful: the Wicked Witch was simply too scary for the kids watching the show!
The concept of the episode is that the WIcked Witch of the West is flying over Sesame Street when she drops her broom. David, a law student working part-time at Mr. Hooper's store, finds it. The Witch storms in, demanding it back, threatening to turn Big Bird into a feather duster. Meanwhile, Oscar the Grouch immediately falls for the nasty witch.
The Witch spends the episode trying to get the broom back, even going so far as to disguise herself as a kindly old woman. There's a meta joke where Mr. Hooper offers the Witch a cup of coffee and she tells him she can't stand the stuff; Hamilton was currently appearing in Maxwell House commercials. By the end of the episode Big Bird has come to like the Witch, and he feels sad when she flies away on her reclaimed broom... which she promptly drops again.
The reaction to the episode was immediate and strong. From the Muppet Wiki:
This episode prompted an unusually large amount of mail responses from parents, almost entirely negative, within a short time frame. Typical responses included parents concerned that their children were afraid and now refused to watch the show, using such phrases as "screams and tears" and "the threat of the witch's power remains in children's eyes." A somewhat atypical missive came from a self-proclaimed Wiccan, concerned with the perpetuation of a negative fairy tale stereotype and recommended a segment "portraying witches as they really are, now."
Due to the overwhelming reaction, additional test screenings were held from March 1 through the 5th, "to assess children's reactions to the Wicked Witch of the West." The tests showed that children were "exceptionally attentive during the Margaret Hamilton segments," and those who watched the episode in color were fascinated by her green face. The issue of fear was difficult to fully judge, due to confusing answers and the fact that the children were surrounded by their peers and adults, and not alone watching. However, due to the parents' reactions, the letter content and testing observations, Anna Herera of the CTW Research Department suggested "that the Margaret Hamilton show not be re-run."
And as far as I know, the episode has never been seen again.
Hamilton was no stranger to PBS kids' shows, by the way. She had appeared on Mister Rogers' Neighborhood in 1975 - although this appearance was as herself, explaining to kids why they shouldn't be afraid of the witch on TV, and explaining the Witch's psychology. That footage still exists:
Now that Disney has the Muppets I'm surprised they didn't try to dig this episode out of storage for Oz The Great And Powerful promotion. Even some web clips would be fascinating to see - a truly suppressed moment in children's television history.