Honestly, it isn't awfully surprising. Bitcoin is seen by many as a get rich quick scheme on the same level as penny stocks or OTM options expiring this Friday. It doesn't surprise me that those people are holding bitcoin (in a misguided attempt to double their money) and are ignorant enough to fall for something like this (in a misguided attempt to double their money).
I once sent an insignificant amount of bitcoin to one of those "honest Ponzi schemes" - that is websites which promise a quick return of 1+x% of your capital while declaring upfront that they will become insolvent, that they are ponzis. Just for the fun of it. I got my 1+x% back. The website shut down very quickly, the authors got scared by how many people decided to play this idiotic game.
It's human nature to play games like this. The whole idea of startup "IPO exit" is really just a ponzi play (if you think the company is good - why the heck would you sell it just as soon as the "dumb money" moves in?).
