Facebook CEO Mark Zuckerberg testified before Congress at a joint hearing of the Senate Judiciary Committee and the Senate Commerce, Science and Transportation Committee following the recent Cambridge Analytica data scandal.
Crowds gathered to watch the outcome of the meeting.
Outside the Capitol building, which houses Congress, online protest group Avaaz created 100 Zuckerberg dummies wearing T-shirts with the words 'Fix Facebook'.
Zuckerberg, who founded Facebook in the hall of Harvard University in 2004, is struggling to prove he is the right person to keep driving what has evolved into one of the world's largest companies.
Facebook is facing a growing crisis of trust among users, advertisers, employees and investors, after acknowledging that up to 87 million people, mostly in the United States, had their personal information stolen from the Cambridge Analytica website. a political adviser who documented US President Donald Trump's campaign to her clients.