In 2019 they raided the Australian national broadcaster's headquarters, and the home of a journalist, because of 'national security secrets' [1].
A couple of days ago, a 21 year old journalist and comedian was arrested by a counter-terrorism unit because he helped make youtube videos criticising a government official [2]. Nothing serious about national security is required anymore.
The laws in Australia are terrifying; the government has extraordinary powers that can force you to build encryption backdoors and you're not allowed to tell anyone, not even your employer. So who knows what happens that the public never hears about.
People were also arrested for making facebook posts just talking about covid protests.