"FILE - In this April 10, 2018, file photo Facebook CEO Mark Zuckerberg looks down as a break is called during his testimony before a joint hearing of the Commerce and Judiciary Committees on Capitol Hill in Washington. Twitter's ban on political advertising is ratcheting up the pressure on Facebook and Zuckerberg to follow suit. Zuckerberg doubled down on Facebook's approach in a call with analysts Wednesday, Oct. 30, 2019, he reiterated Facebook's stance that ""political speech is important."" (AP Photo/Andrew Harnik, File)"