In 2019, Facebook announced its plan to roll out a new stablecoin called Libra. In 2020, Libra was renamed as Diem. In 2022, after failing to obtain the blessing of the U.S. regulators, Facebook (now called Meta) finally decided to wind down Diem. Please tell us the story of Libra/Diem. What were the major concerns of the U.S. regulators? .