Following a slew of controversies this year, Facebook's share price declined by more than 20 percent during after-hours trading.
Facebook said political consulting firm Cambridge Analytica accessed data on 87 million people—not 50 million as previously reported.
Mozilla pauses advertising on Facebook following the recent controversy but may resume when the social network strengthens its default privacy settings.
Tech CEOs Mark Zuckerberg, Tim Cook and Satya Nadella all voiced their stance against hate, neo-Nazis and white supremacism.