NEW YORK — Mark Zuckerberg’s fortune dropped $4.9 billion on paper Monday as investors weighed reports that a political advertising firm retained information on millions of Facebook Inc. users without their consent.
Facebook said Friday that Cambridge Analytica, the advertising-data firm that helped Donald Trump win the U.S. presidency, received user data through an app developer on its social network, violating its policies. The company harvested private information from the Facebook profiles of more than 50 million users without permission, the New York Times reported.
It was a punishing day for other tech billionaires too. Amazon.com Inc.’s Jeff Bezos lost $2.1 billion (all figures US) and the fortunes of Alphabet Inc. founders Larry Page and Sergey Brin each declined $1.5 billion as a technology selloff sent the Nasdaq indexes to the steepest losses in six weeks.