Today: Facebook CEO Mark Zuckerberg testifies to Senate committees in joint hearing on data privacy; protesters supporting the #DeleteFacebook movement rally outside the Capitol; Pres. Trump meets with the Emir of Qatar; Justice Ruth Bader Ginsburg moderates naturalization ceremony for 200 candidates at the New York Historical Society; Pres Trump hosts the 2017 NCAA Football National Champions: the Alabama Crimson Tide on the South Lawn of the White House; and all live events and breaking news from FOX5DC digital. Molly Nevola and Samantha Silver host.