https://www.theguardian.com/technology/2018/jul/26/facebook-market-cap-falls-109bn-dollars-after-growth-shock

Three million European users abandon platform after Cambridge Analytica breach revealed

More than $109bn (£83bn) has been wiped off Facebook’s market value, including a $14.5bn hit to the fortune of founder Mark Zuckerberg after the company warned investors that user growth had slowed in the wake of the Cambridge Analytica data leak scandal.