Security breaches of hotel guest data are not uncommon, but few have been quite on the scale of the most recent incident involving 500 million Starwood Hotels guests.

On Friday, Starwood owner, Marriott International, which bought Starwood Hotels & Resorts in 2016 for $13.3 billion, revealed it had recently discovered a massive security breach involving guests who had stayed at Starwood-branded properties from 2014 to September 10, 2018.

Guest information that may have been hacked included credit card information and passport numbers. The potential blowback on Marriott is still unfolding.

Marriott discovered the breach on September 8 and the incident, according to Marriott spokesperson Connie Kim: We have successfully contained the incident, although this continues to be an ongoing investigation. Its not clear why Marriott chose to disclose the breach on Friday.

But at a time when the worlds largest hotel company has dealt with one of the largest ever hotel worker strikes on record, as well as mounting dissatisfaction from disillusioned Starwood Preferred Guest (SPG) loyalty members who have expressed their displeasure with the merger of SPG with Marriotts own Marriott Rewards program, news of this security breach will be yet another setback for the worlds largest hospitality company.

Read the full article at skift Inc.