https://www.reuters.com/article/us-usa-fed-brainard/facebooks-libra-faces-core-legal-regulatory-challenges-brainard-idUSKBN1WV2HW >U.S. Federal Reserve Governor Lael Brainard said on Wednesday that Facebook's efforts to launch a Libra cryptocurrency must overcome a "core set of legal and regulatory challenges" before facilitating a single payment.