LONDON (AP) — A cohort of international lawmakers is trying to turn up the pressure on Facebook, grilling one of its executives and making a show of founder Mark Zuckerberg's refusal to explain to them why his company failed to protect users' data privacy.

The rare "international grand committee" of lawmakers from nine countries gathered in London to get answers about Facebook's handling of personal data and made a point of leaving an empty seat with Zuckerberg's name tag.