Aussie here.

This tweet is bullshit and the news article they link references the previous government, so it's obviously old. A lot of dumb shit gets recommended to the government in various reports, doesn't mean it gets legislated.

Sadly, the police in Australia can already access your social media with a warrant, and can even edit and delete posts if you're the subject of an ongoing investigation, as part of anti-terrorism laws that were passed last year. It was supported by both major political parties, so they are both a bunch of cunts IMO.