SYDNEY - Social media giant Facebook took the extraordinary step of blocking news sites in Australia in a move that appeared to be designed to send a message to both Australia and the world about attempts to force it to pay media publishers for content.

Facebook's move - which it said it took with a "heavy heart" - shocked Internet users in Australia and internationally, as Australians suddenly discovered on Thursday (Feb 18) that they could not view or share content by news sites from Australia or overseas. Users outside Australia were barred from viewing or sharing content from Australian news sites.

Facebook's move prompted an immediate public backlash in Australia, especially as the ban accidentally blocked content from non-news sites such as emergency services pages and the official weather bureau.

The ban was condemned on social media as excessive and self-defeating. One comment on Twitter said: "Just give Facebook the flick. It's truly liberating." Others suggested migrating to Myspace.

Health experts criticised Facebook for banning hospital and medical sites, just days before Australia begins its rollout of Covid-19 vaccines. The ban also removed content from three MPs in Western Australia ahead of a state election, prompting the premier, Mr Mark McGowan, to say: "They're behaving more like North Korea than an American company."

Facebook even blocked access to its own page, prompting a German on Twitter to write: "Can they also ban themselves elsewhere?"

Facebook later said it was reversing any bans which it had imposed "inadvertently".

The firm imposed the ban to demonstrate its fierce opposition to the federal government's proposed news media code, which would require Facebook and Google to negotiate with media companies to pay them for content posted on their sites. The ban was imposed early Thursday morning, hours after the media code was passed in Parliament's Lower House. It is yet to be passed by the Upper House.

Australian Prime Minister Scott Morrison strongly condemned Facebook's "arrogant" ban, saying it would only add to concerns in the international community about the conduct of global technology giants.

"I am in regular contact with the leaders of other nations on these issues," he said in a statement.

"These actions will only confirm the concerns that an increasing number of countries are expressing about the behaviour of BigTech companies who think they are bigger than governments and that the rules should not apply to them."

The managing director of Facebook Australia and New Zealand, Mr William Easton, said the company imposed the news ban with "a heavy heart". He said Facebook assists media publishers by helping to funnel users to news sites.

"The value exchange between Facebook and publishers runs in favour of the publishers," he said in a statement. "For Facebook, the business gain from news is minimal."

Google also recently threatened to protest Australia's new code by blocking access for all Australians to its search engine, but eventually opted - unlike Facebook - to make deals to pay publishers.

As Facebook began blocking Australians news sites, Google and Mr Rupert Murdoch's News Corp revealed that they had signed a three-year deal in which the search engine will pay for content from news sites around the world, including The Wall Street Journal, The Times in Britain, and The Australian. The deal involves Google and News Corp developing a subscription platform as well as investment in video journalism. Google has been making other deals with publishers, including in the United Kingdom, Germany and Brazil.

Australia has been one of the world's most proactive countries in trying to force Facebook and Google to pay for news content featured on their sites. This follows concerns in many countries that - in this era of fake news - media outlets are struggling to survive, partly because they receive relatively little revenue from their content distributed online. According to Australia's competition authority, Google received 53 per cent of online advertising revenue in Australia in 2019, while Facebook received 28 per cent and news and other online sites received 19 per cent.

Australian Treasurer Josh Frydenberg spoke to Facebook CEO Mark Zuckerberg for 30 minutes on Thursday, saying he was hopeful of reaching a deal.

"We want them to remain in Australia, but we also want them to pay for original content," Mr Frydenberg said.

Some commentators questioned Facebook's move, saying it may push users to other social media sites.

Dr Nicole Bridges, a social media expert at Western Sydney University, told The Australian Science Media Centre on Thursday: "In this age of misinformation, fake news and the proliferation of conspiracy theories, this is a dangerous move by the tech giant."