In my opinion, this Facebook decision is the right decision. I can't imagine what losses Facebook will suffer if Facebook really bans advertisements about crypto currencies on its platform. Most crypto currency players and investors use Facebook as a communication medium so that if Facebook prohibits crypto currency they will automatically stop using Facebook. Of course this is a pretty drastic loss that will be experienced by Facebook. In my opinion, Facebook can still allow crypto currency ads but with some conditions that previously Facebook will conduct an investigation to ensure that the ads on Facebook are truly real and not a fake project. This must be done by Facebook to become a trusted and professional social media forever.