The cyberattack targeting the personal data of customers with Qantas is the latest in a string of breaches affecting millions of Australians, as hackers target major companies and exploit weak spots in the systems they rely on.

The hack of the Australian carrier follows recent incidents at Hawaiian Airlines and Canada’s WestJet. Here’s what you need to know. Qantas said on Wednesday it is contacting customers after a cyberattack targeted a third-party customer service platform that stored the personal data of 6 million customers.

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.