Facebook has stopped publishers and people in Australia from reading or sharing news content on the platform.
The announcement comes in response to proposed new laws in Australia that would force tech companies to negotiate with media companies over how much to pay them for news content.
It would also require that local media got 28 days' notice of any changes to the crucial algorithms that decide how news is ranked, presented and advertised around on the likes of Facebook and Google - a crucial move that would help shift the power balance, a little, in the favour of traditional media.
However, the first hours of the ban have not gone smoothly with non-news services including police, weather, emergency, weather and health sites caught up in the ban - hindering the flow of information as Australia prepared for its first round of vaccinations (see examples below).
Other organisations from Harvey Norman to the Australian Council of Trade Unions found their Facebook pages blocked. Facebook Australia's own home page was reportedly inaccessible.
AUT media researcher Merja Myllylahti said, "Unfortunately, Facebook has shown again that is not for democracy. It is antidemocratic."
Facebook initially threatened to pull news content in August, early in discussions surrounding the proposed new Media Bargaining law.
But the decision to impose the ban comes as legislation is set to be debated in parliament ahead of being voted into law.
Facebook Australia & New Zealand managing director William Easton defended the shock call in a lengthy statement.
"The proposed law fundamentally misunderstands the relationship between our platform and publishers who use it to share news content," he wrote.
"It has left us facing a stark choice: attempt to comply with a law that ignores the realities of this relationship, or stop allowing news content on our services in Australia.
"With a heavy heart, we are choosing the latter."
The ban seems to stop people from all around the world seeing news from Australia. A Herald attempt to post a link to an Australian story - from New Zealand - failed. Others reported similar experiences.
In the first hours of the ban, multiple non-news sites were also made inaccessible to Australian's on Facebook - presumably because a mass cull was being undertaken in part by algorithms.
It was reported that Facebook had removed the Australian Bureau of Meteorology page amid floods in Queensland and fires in Western Australia. The Department of Fire and Emergency Services WA was also blocked.
Others complained it would disrupt the flow of information about Australia's Covid-19 vaccination programme which, like New Zealand's, is about to begin.
State health departments found themselves blocked from Facebook.
An attempt by Victoria Police to post content to Facebook also failed.
The Australian Council of Trade Unions called it disgraceful as its sight was also blocked.
Retailer Harvey Norman had its home page blocked.
Some users even posted screen grabs of content on Facebook Australia's own home page being blocked.
A Facebook Australia-New Zealand spokeswoman told the Herald several hours into the ban, "Government Pages should not be impacted by today's announcement. The actions we're taking are focused on restricting publishers and people in Australia from sharing or viewing Australian and international news content. As the law does not provide clear guidance on the definition of news content, we have taken a broad definition in order to respect the law as drafted. However, we will reverse any pages that are inadvertently impacted."
A "combination of technologies" was being used to implement the ban, the spokeswoman said.
The discussion involving the proposed law centred on American-based tech firms such as Facebook, and how they benefited from news being shared on their platforms.
But Easton argued that Facebook's platforms "have fundamentally different relationships with news".
"Google Search is inextricably intertwined with news and publishers do not voluntarily provide their content. On the other hand, publishers willingly choose to post news on Facebook, as it allows them to sell more subscriptions, grow their audiences and increase advertising revenue," he said, claiming the arrangement worked in publishers' favour.
"Last year Facebook generated approximately 5.1 billion free referrals to Australian publishers worth an estimated AU$407 million," he posted.
"For Facebook, the business gain from news is minimal. News makes up less than 4 per cent of the content people see in their News Feed.
"Journalism is important to a democratic society, which is why we build dedicated, free tools to support news organisations around the world in innovating their content for online audiences."
Less than an hour after the announcement, Facebook had pulled content from Australian media site's Facebook pages.
Late last year, the Australian Competition and Consumer Commission slammed the then-threat to ban news in Australia.
"The draft media bargaining code aims to ensure Australian news businesses, including independent, community and regional media, can get a seat at the table for fair negotiations with Facebook and Google," ACCC chairman Rod Sims said in a statement at the time.
"Facebook already pays some media for news content. The code simply aims to bring fairness and transparency to Facebook and Google's relationships with Australian news media businesses."
After initially burying Australian news search results and threatening to pull its search engine from Australia, Google has over the past few days begun announcing a series of deals with Australian publishers, including the Rupert Murdoch-owned News Corp, to pay for content.
- Additional reporting by news.com.au