https://www.reuters.com/article/us-facebook-cambridge-analytica-congress/u-s-house-panel-formally-asks-facebook-ceo-to-testify-on-user-data-idUSKBN1GZ25A >The leaders of the U.S. House Energy and Commerce Committee on Friday wrote Facebook Inc chief executive Mark Zuckerberg detailing new concerns about the social media company's use of data and formally requesting that he testify at a future hearing.