Marriott says as many as 500 million Starwood guests’ data may have been breached. The company determined the breach in their guest reservation system dating back to 2014. If you have made a reservation on or before September 10th 2018, consider your information at risk. The exposed information includes names, phone numbers, email addresses, passport numbers, date of births, and rewards account numbers. For 327 million guests, it added the exposing of their credit card information taken.