Here’s another favorite from my collection. This is a teasing hoax that dates back to at least 1989. It’s aimed at people who don’t know much about chemistry or are actively afraid of anything that smacks of “chemistry” (or sometimes even science). You can read about it on Wikipedia, or you can visit the official site. (Yes, it’s a hoax with an official website.)
I’ve seen an episode of the Penn & Teller cable show, Bullshit, where they send people out with petitions about DHMO to see how many signatures they could get. Many people accept it as dangerous without really understanding it.
It speaks to an interesting combination of fear and willingness to trust (or not) information based on certain attributes!