BETHESDA, Md. — A security breach inside Marriott's worldwide hotel empire has compromised the information of as many as 500 million guests, exposing in some cases credit card numbers, passport numbers and birthdates, the company said Friday. Alarming security analysts, Marriott said that unauthorized access to data within its Starwood network has been taking place since 2014 in what may be among the largest data breaches on record. Marriott acquired Starwood in 2016 and the process of merging its computer system with Starwood computers has been marred by technical glitches.