Facebook founder and CEO Mark Zuckerberg is facing his second day of testimony before the U.S. Congress on the social media giant’s treatment of user data in the wake of the Cambridge Analytica scandal. Zuckerberg will take questions today before the House Energy and Commerce Committees.

Yesterday, in his testimony before the Senate Committee on the Judiciary and Senate Committee on Commerce, Science, and Transportation, Zuckerberg admitted employees were working with the Mueller investigation into Russian meddling, and also that he did not know about terms and conditions that put Facebook on notice that millions of users’ data would be sold. The social network has acknowledged that the public profiles of its 2 billion users might have been collected without their knowledge or permission.

Facebook has also been on the front lines of a fight against Russian interference in the 2016 U.S. presidential election, with some 126 million users potentially having been exposed to content produced and circulated by outside propagandists trying to foment discord. Some in D.C. have suggested the need for government regulation, to which Facebook’s Cheryl Sandberg has said the company is open.

Stay tuned for Deadline’s coverage of the hearing.