https://phys.org/news/2018-12-breaches-marriott-treasure-troves-spammers.html

Marriott, the world's largest hotel chain, said last week that its Starwood guest reservation database has been hacked and that the personal information of up to 500 million guests had been exposed. The majority of the victims in the Marriott breach, believed to be 317 million people, had a combination of their names, addresses, passport numbers, dates of birth, phone numbers, gender, email addresses, and reservation information stolen.

The methods used to hack the reservation system, the ability of Marriott to protect itself against breaches, and how the stolen data could be used all remain unclear. But Lu said that the hack exemplifies how sophisticated cyberattacks have become, the need for businesses to invest more resources in protecting their data, and the demand for laws that set industry standards for cybersecurity.