The New York Attorney General is opening an investigation into a Marriott data breach that may have affected 500 million guests.

In a tweet Friday, Attorney General Barbara Underwood said residents need to know that their personal information is safe.

Marriott says that unauthorized access to data at former Starwood hotels, which Marriott acquired two years ago, has been taking place since 2014.

The affected hotel brands include W Hotels, St. Regis, Sheraton, Westin, Element, Aloft, The Luxury Collection, Le Méridien and Four Points. Starwood branded timeshare properties are also included.

None of the Marriott-branded chains are threatened.