U.S. Treasury Secretary Janet Yellen said at a Senate Banking Committee hearing on Thursday that the Treasury Department could use more powers to combat the use of cryptocurrencies by terrorist groups. "We do have a lot of authority to take action, but we have identified some of the loopholes and made a series of recommendations on how to strengthen Treasury's authority," Yellen said. Senator Mark Warner asked Yellen if she thought the Terrorist Financing Prevention Act was necessary, and Yellen responded: "I recognize that the Treasury Department faces some constraints, and we certainly support the goals of this bill. It will help give us the authority to make We are better equipped to deal with a very significant threat."