Hundreds of millions of phone numbers linked to Facebook accounts have been found online.
The exposed server contained more than 419 million records over several databases on users across geographies, including 133 million records on U.S.-based Facebook users, 18 million records of users in the U.K., and another with more than 50 million records on users in Vietnam.
But because the server wasn’t protected with a password, anyone could find and access the database.
https://techcrunch.com/2019/09/04/facebook-phone-numbers-exposed/