On March 31 Marriott International announced that it suffered a data breach affecting more than 5 million people. The app it uses to service guests was hacked in mid-January. The breach was discovered in at the end of February, and the company began its investigation. Information compromised includes contact details of hotel guests, and information about members of the Marriot loyalty program such as company, gender, birth date and affiliations with partnering loyalty programs at airlines, etc. The company has set up a website where customers can see if their information was involved. The nakedsecurity site quotes a security expert who says that this is the type of breach that can be problematic for consumers, because it provides good raw material for cybercrime. In 2018, the names, addresses, contact information and passport numbers of over 300 million people who stayed at a Starwood hotel property were accessed in a major data hack. Marriott had just acquired Starwood, and said that the hacking may have been going on since 2014.