Marriott data breach affects up to 500 million

Marriott on Friday announced a massive data breach that compromised the information of as many as 500 million guests at its Starwood hotels. The company said that it discovered unauthorized access within its Starwood reservation network, which includes Sheraton, Westin, and other hotel brands, has been occurring since 2014. Some guests’ credit card numbers and expiration dates could have been taken, according to the company. Other potentially exposed data include mailing addresses, phone numbers, email addresses, passport numbers, Starwood Preferred Guest account information, dates of birth, genders, arrival and departure information, reservation dates, and communication preferences. Exactly how much data was hacked varies among guests.

Marriott will begin sending emails Friday to individuals who may have been affected. The company has set up a website and call center for people who are concerned about their information. Analysts have not finished identifying duplicate information in the database, so the number of individuals affected may be less than 500 million and include people with multiple stays, Marriott spokesman Jeff Flaherty said.

Editor’s note: This report has been updated to reflect the data breach only affected the Starwood reservation system.