If you made a reservation at a Marriott property over the years, there might be cause for concern.

On Friday, Marriott announced a breach of their Starwood reservations system. The hack exposed information on reservations made on or before September 10th, 2018.

The data breach could have information on as many as 500 million guests. During their investigation, Marriott found out their systems could have been accessed back to 2014. Starwood hotels include Sheraton, W, Aloft and other hotels and resorts.

Marriott will start emailing people in their database to offer them free online account monitoring for a year.

Source: https://www.bbc.com/news/technology-46401890