Five members of Congress have called Facebook to half Libra development in an open letter to CEO Mark Zuckerberg and executive David Marcus. The letter cites Facebook's track record with private user information as well as the implications of a global currency. "[T]hese products may lend themselves to an entirely new global financial system . . . intended to rival U.S. monetary policy and the dollar," the letter reads. "This raises serious privacy, trading, national security, and monetary policy concerns for not only Facebook’s over 2 billion users, but also for investors, consumers, and the broader global economy."