J D Wetherspoon has revealed data belonging to some customers in the UK including names and email addresses may have been stolen by hackers in June.
It says it only found out about the breach of its old website two days ago.
The Pub chain also claims some limited credit or debit card information was stolen but doesn't think it could be used for fraudulent activity.
It's unclear if any customers of JD Wetherspoon's Irish premises have been affected.