A unit of the U.S. Treasury is eyeing the "virtual" currency commonly used in games, saying it suspects companies of money laundering through the currency. The department says it will regulate the products of currencies such as Bitcoin as it now does the money exchanged through traditional wire services such as Western Union. It is not clear whether the new regulations apply to such online currency as Amazon Coins, however. "We are beyond the stage where this was just funny money and a fun online thing. This is used as a currency," said Nicolas Christin, associate director of the Information Networking Institute at Carnegie Mellon University.