An activist wearing a mask of Facebook CEO Mark Zuckerberg stands outside Portcullis House in Westminster as an international committee of parliamentarians met for a hearing on the impact of disinformation on democracy, in London on Nov. 27, 2018. Lawmakers from nine countries grilled a Facebook executive who came in place of Zuckerberg on Tuesday as part of an international hearing at Britain's parliament on disinformation and "fake news." [Photo: AP/Frank Augstein]"

An activist wearing a mask of Facebook CEO Mark Zuckerberg stands outside Portcullis House in Westminster as an international committee of parliamentarians met for a hearing on the impact of disinformation on democracy, in London on Nov. 27, 2018. Lawmakers from nine countries grilled a Facebook executive who came in place of Zuckerberg on Tuesday as part of an international hearing at Britain's parliament on disinformation and "fake news." [Photo: AP/Frank Augstein]"

An activist wearing a mask of Facebook CEO Mark Zuckerberg stands outside Portcullis House in Westminster as an international committee of parliamentarians met for a hearing on the impact of disinformation on democracy, in London on Nov. 27, 2018. Lawmakers from nine countries grilled a Facebook executive who came in place of Zuckerberg on Tuesday as part of an international hearing at Britain's parliament on disinformation and "fake news." [Photo: AP/Frank Augstein]"

An activist wearing a mask of Facebook CEO Mark Zuckerberg stands outside Portcullis House in Westminster as an international committee of parliamentarians met for a hearing on the impact of disinformation on democracy, in London on Nov. 27, 2018. Lawmakers from nine countries grilled a Facebook executive who came in place of Zuckerberg on Tuesday as part of an international hearing at Britain's parliament on disinformation and "fake news." [Photo: AP/Frank Augstein]"