Usd is used as funding for illegal activities, it applies to every currency in circulation right now, in fact we only see the USD currency most often used for the activity , perhaps because this currency has a large enough value and the effect is large enough, so not a few of the group groups that use it for illegal acts, the currency misuse depends on how a person uses it, we only have to use it wisely
i think it can be seen from purpose of its use, because i think it is global currency used as basis of other currencies, so more flexible when used for transactions between countries, it is used by people who are not responsible
The possibility is already given, since bitcoin has a value and it's money, therefore it can be use in any transaction.
But, its more easy to track using bitcoin so people who are doing like this illegal transaction can easily be caught, now the government is more focus on regulating the crypto.