The biggest crypto-ponzi, the PlusToken get caught, or at least some of the operators, in China. The police had seized stolen crypto, worth currently over 4 billion USD. As the scheme collapsed in 2019, the loss of the victims was estimated at 2,9 billion USD, but since then there are significant price-gains in some of the assets.
The scams may have some crypto-only specifications but in general, all using human greed and neglect behavior, and the methods are the same, as the classic scams have. Many experts told about the PlusToken, like fraud, and unsustainable pyramid-scheme, but people had believed the lies and the marketing, despite the obvious warning signs.