Promoters ‘pump’ up the price of a security creating a speculative frenzy, then ‘dump’ some of their holdings at artificially high prices. Ernst & Young estimates that 10 per cent of the money raised for initial coin offerings has been stolen.

http://www.news.com.au/finance/money/investing/it-makes-no-sense-former-paypal-ceo-says-bitcoin-is-the-greatest-scam-in-history/news-story/3ab1193c520f6eba1dafa1100e144726