It's only human to desire an easy path to money, excitement, and a better life. And there will always be con artists who take advantage of that desire, no matter if the plan is legal or not. The common sense rule for these schemes is that if it seems too good to be true, it probably isn't true at all. At least it warrants further research on your part before parting with any money.
The title of this video is "The Most Insane Ponzi Schemes In History," but that in itself is deceptive, because the 12 stories include only two people who ran Ponzi schemes, Charles Ponzi and Bernie Madoff. Six or seven were imposters, who profited by being someone they weren't, and the rest were just plain con artists. We can learn something from all of them, even if the lesson is that too many people are just too gullible.