We heard that crypto is often used for terrorist funding, but according to IOCTA in 2018, such an assumption is wrong.
Today, the popularity of Bitcoin is getting better, but the relationship with terrorist funding, they prefer the classic method of transferring through banks.
so, terrorist groups that use bitcoin are only low level transactions.
Bitcoin can be used for any transaction but use it for funding terrorist is not a good idea. As the traceable transactions of bitcoin then law enforcement can track any evil transactions, like they have done with silk road. Fiat is better to fund terrorist because most of transactions are not recorded.