Every thing is life has its pros and cons. If they say crypto currency is bad because it is used by criminal, money laundry and for drugs they are not wrong in saying that for some use it for that purpose . Fiat currencies are used by some people for the same bad things
And I think that the reason terrorists are not so perfect that would go to the new calculation system and more effectively to escape. They are accustomed to using cash, which they do. It would be better to cut the dollar, and not the crypto currency.