Australian airline Qantas said that a hacker made off with a trove of customers’ personal data including passenger names, emails, phone numbers, birth dates and frequent flyer numbers.

Australian airline Qantas says a data hack on Monday exposed the personal information of six million customers and it expects the amount stolen to be “significant.”

Millions of Aussies have been impacted by the shock cyber hack on Qantas, which extracted sensitive customer data including names, emails, phone numbers, birth dates and frequent flyer numbers.