The Australian Government has just released a proposed law to deal with defamation and social media comments.
See Social Media (Anti-Trolling) Bill.
The AG's office provides the following information:
"The challenges of responding to anonymous online trolling became clear after the High Court's decision in Fairfax Media Publications v Voller  HCA 27, handed down in September 2021. The Voller
decision shows that Australians who maintain a social media page may be
exposed to defamation liability for defamatory comments posted on the
page by others – even if they are not aware of those defamatory
To urgently address this situation the Australian Government has
developed the Social Media (Anti-Trolling) Bill 2021. To address the
implications of the Voller decision, the Bill will protect
Australians from defamation liability that could arise if they allow
users to comment on their social media page."