The biggest crime to hit the crypto ecosystem I could think of right now is waking  up the next day and realizing that the entire  bitcoin blockchain network is no more to the extent that no one can't trace the entire Bitcoin network. I believe that day in the world history will be labeled as the dark day of digital currency. About Trillions of dollars will be lost within one day with no traces that can help in the  retrieval  of even a cent of this lost money.