I think people with a criminal mind ready to act on and undertake illegal activities don't care whether it is fiat or crypto as long as they can obtain them with minimal effort and get away with it.

That said, only crypto with less involved 'hacking' due to required expert knowledge would be at higher risk, while fiat would be at the top. We need to remember that for now crypto is still in its early days and it would take time until criminals would adopt crypto as their main strategy, like fiat is today, and there are plenty of articles written on exactly this.