On Friday, Marriott International announced that the information shared by up to 500 million guests may have been exposed as part of a massive data breach. According to NBC News, an "unauthorized party" had been accessing and copying reservation information from its Starwood database since 2014. For 327 million guests, data taken includes things such as name, address and phone number, email address, or even passport number. Others may have had credit card info compromised. "We deeply regret this incident happened," Marriott President and CEO Arne Sorenson said in a statement. "We fell short of what our guests deserve and what we expect of ourselves. We are doing everything we can to support our guests, and using lessons learned to be better moving forward." Marriott is the world's largest hotel chain, as its portfolio includes the W, St. Regis, Westin, and Sheraton Hotels.