Of course there are many criminal and terrorist organizations that use bitcoin as a way of circulating money for transactions.
I agree that some of the drug dealers accept payments in Bitcoins and other form of crypto-currency such as Monero, Ethereum and Bitcoin Cash. But I have never heard of the mafia gangs and cartels using Bitcoins. That is because they are having far better options. Many of the mainstream banks help the mafias to launder their money.