“Now that’s not a free country where that happens. That’s not right. They should have to identify who they are.
“People should be responsible for what they say in a country that believes in free speech.”
Mr Morrison said companies that did not allow for the identification of people should no longer be considered a platform, but a publisher.
He also flagged the government would be “leaning further” into concerns around a lack of accountability online.
“Australia has been more forward-thinking and advanced when it comes to holding big social media companies to account,” he said.
“We value our free society. And in a free society, you can’t be a coward and attack people and expect not to be held accountable for it.”
The prime minister’s comments came following his deputy’s calls for a major crackdown on social media giants.
Deputy Prime Minister Barnaby Joyce on Thursday hit back at “completely and utterly fictitious” rumours about his family on social media, suggesting former NSW Nationals leader John Barilaro’s retirement from politics was because he was in a relationship with one of Mr Joyce’s daughters.
“It’s total and utter rubbish,” Mr Joyce told ABC radio.
He said it was essential that more was done to force social media companies like Facebook and Twitter to stop people spreading lies.
“From my own personal experience of recent times, you have got to get to a point where you say enough is enough,” he said.
“These platforms just say ‘oh well it’s too hard to control’.”
Mr Joyce said he would speak to US politicians who are conducting a congressional inquiry that unearthed explosive allegations against Facebook.
Frances Haugen – a former Facebook data scientist – told a hearing the company was dishonest about efforts to counter misinformation and knew Instagram, which is also owned by Facebook, could have a toxic effect on young girls.
The deputy prime minister said it wasn’t just about his daughter’s experience but a broader problem across society.
“The idea that someone can have this sort of pseudonym on Twitter and say the most outrageous things, and we in 2021 just sit back and say ‘that’s fair enough’ – that’s got to stop,” Mr Joyce said.
Facebook chief Mark Zuckerberg has described Ms Haugen’s testimony as false and insists the company cares deeply about safety.
Communications Minister Paul Fletcher on Wednesday said the “special treatment” online companies had gotten away with was no longer acceptable to the community or government.
Mr Fletcher also did not rule out laws to crack down on Facebook or other social media networks over misinformation.
Separately, Defence Minister Peter Dutton’s court case against refugee activist Shane Bazzi over a deleted social media post continued on Thursday.
Mr Dutton has told the Federal Court he was “deeply offended” by a tweet calling him a “rape apologist” as the insult “went against who I am”.
The Queensland MP says the now-deleted tweet from 25 February suggested he condones and excuses rape.
Mr Bazzi has said that a reasonable reader wouldn’t have interpreted the tweet in that way, given the context.
The High Court ruled in September that media outlets can be sued over defamatory comments made by their audience on Facebook news articles.
The court’s decision on what makes a “publisher” could lead to non-profits, community groups and police forces more tightly controlling comments on their Facebook pages.