More than half a billion records of millions of Facebook users have been found exposed on unprotected Amazon cloud servers. The exposed datasets do not directly come from Facebook; instead, they were collected and unsecurely stored online by third-party Facebook app developers. One dataset contains over 540 million Facebook user records, including comments, likes, reactions, account names, Facebook user IDs, and more. Both datasets were stored in unsecured Amazon S3 buckets, which have now been secured and taken offline.
Source: https://thehackernews.com/2019/04/facebook-app-database.html