Over 100,000 current and former Optus customers are part of a class action lawsuit over the data breach that occurred on its systems last year.
A class action is when multiple people sue a defendant for the same or similar reasons.
The breach affected up to 10 million people. Home addresses, customer names, and phone numbers were compromised in the cyberattack.
First, the Optus data breach
Optus was subject to a data breach from an external force in September last year.
It was conducted by a sophisticated hacker, whose IP address was unable to be located. About 10,000 customers had their personal details published on the dark web.
There have since been cyberattacks on other large Australian businesses, including Medibank and Latitude Financial Services.
The class action lawsuit
The class action was lodged in the Federal Court on Friday by Slater & Gordon.
All current and former Optus customers whose personal information was compromised in the breach will have the option to join the lawsuit.
The lawsuit is seeking costs for the time and money spent to protect their privacy after the hack, and compensation for the emotional impacts caused.
Slater & Gordon said that Optus provided a dissatisfying response to some of its customers after the data breach. Plaintiffs allege that Optus failed to clarify to them what personal data had been stolen and refused to pay for credit monitoring services to some former customers.
The class action accuses Optus of failing to take reasonable steps to protect the personal information of current and former customers.
They say this breached their contract and duty of care with Optus customers, and also broke Australian law.