I recently finished listening to this series from the BBC.
Not only is it a wild ride of a story, it's also a great educational tool for the difference between bitcoin and crypto. One of the best podcasts I have ever heard. 
Discussion
I was amazed by the viral power of MLM schemes and how easy it was for them to redirect their networks to the latest scam. (Brought back high school memories of joining my friend and his mom at a Amyway event.)
I was particularly surprised by their ability to penetrate Africa. Never expected that