In November 2018, Marriott announced a data breach where there was unauthorized access to their Starwood Preferred Guest reservation system and that the data for up to 500 million guests had been compromised. In an update today, Marriott has stated that the amount of affected customers is lower than expected at 383 million. In the update, they have also stated that 5.25 million unencrypted passport numbers and 20.3 million encrypted password numbers were accessed. The original Starwood reservation database is now shutdown as part of their merger with Marriott.
Source: https://www.bleepingcomputer.com/news/security/525-million-unencrypted-passport-numbers-accessed-in-starwood-breach/