I don't think not processing their transactions is a good move at all because one of the biggest steps done by the authorities is tracking them through the transactions they have made and simply not just blacklisting all the transactions they are seeing.  I know the authorities have the power to do these but I don't think they want this to happen in the first place that's why we only see enforcement of KYC and AML procedures from happening to the Bitcoin network and also of course them knocking to all the crypto related services we have as the more coverage they have the more chances they can track down these criminals.