Quoting from...

Quoting from https://www.slatergordon.com.au/class-actions/current-class-actions

"How do I start my own class action?

In Australia, Class Actions take place in the Federal Court and State Supreme Courts.

There are three criteria that need to be met for a lawsuit to take place:

1. There must be 7 or more people claiming;
2. From the sale, or similar, event/circumstances; and
3. The claim must relate to at least one common issue of law or fact.

Australian Class Actions work an opt-out model. This means that all people affected by the event or circumstance become members of the action whether they intended to or not. These members are bound by the decision of the court or settlement unless they opt-out of the proceedings. If you are involved in a class action you will be notified."