Crypto being dragged to illegal things, it's no longer a question but a reality that even terrorist are learning this industry, they knew how to take advantage and how they can manage to hide those illegal acts that they are doing. It's the government who needs to counter this and they need to have strict policies once incident like this being proven to exist inside their jurisdictions.
but if the crypto user is regulated by a third party like the government then I think it will be difficult. crypto is known as a free currency, I think it will need a special study to solve this problem because I think the use includes abuse