Conspircacy theories

This week I thought we could talk about conspircacy theories. Do you know of any? Do you know anyone who believes them?

They seem to be on the rise in the United States. This article lists a few and tries to understand why people believe them:

https://www.scientificamerican.com/article/why-do-people-believe-in-conspiracy-theories/

This article also talks about why people are prone to believe in conspiracy theories.  If you click on the blue circle (with the white triangle inside) in the top right hand corner of the page, you can listen to the interview:

http://www.npr.org/2016/12/11/505187974/why-people-believe-conspiracy-theories

I thought about including a link with a list of some popular conspiracy theories, but I think it will be more fun for you to find one or two and explain it to the rest of the group.