In November 2018, Marriott announced that 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, but that 5.25 million unencrypted password numbers were accessed.

https://www.bleepingcomputer.com/news/security/525-million-unencrypted-passport-numbers-accessed-in-starwood-breach/