The U.S. treasury department does have the authority to work with central banks and commercial banks in many countries as part of pre-existing counterterrorism authorities. There's a lot of global cooperation on trying to block terrorist financing.
As you interpreted from our own earlier remarks, some of their financial schemes are very local. We're not on the ground in Syria. We're not physically present in Mosul and some of the towns that they're controlling in western Iraq. I think that we—if you mean we as North Americans—are not directly involved in trying to block their finances. I think we're trying to help the Iraqis and Syrian opposition to do the best they can.
But I don't believe, to the best of my knowledge, that ISIL is depending on funds that are transiting internationally. They are getting their resources locally or through donations that come through informal networks and channels.