The shooting had barely finished before the false information began to spread, formed in corners of the internet governed by alternative facts.
According to Grok, the artificial intelligence platform on X (formerly Twitter), a man named Edward Crabtree was the hero who risked his life to disarm one of the attackers. Crabtree even had an entire life story. Only problem -- it was complete fiction.
There were also, allegedly, other attacks happening simultaneously across Sydney, fuelling further fear and paranoia.
"If there are not a lot of facts out there, it will always be filled with whatever is available, and quite often the initial information is very low quality," said Dr Anne Kruger, a mis and disinformation expert from the University of Queensland.
"The plural of anecdote is never a fact. We're seeing the same thing, the laundering of information through social media."
The term fake news may have been popularised by Donald Trump, but misinformation is not new. It is, however, a huge concern as people turn to social media and AI platforms for the latest information.
"It is categorically easier to make fake information than wait for reliable sources to report it," said Nathan Ruser, an analyst with the Australian Strategic Policy Institute. "If something is believable, the narrative can escape much quicker than reality."
There were many false narratives steaming through the internet on Sunday night as two suspected gunmen opened fire at a Hanukkah event next to the iconic Bondi Beach.
Here were five of them.
1. Edward Crabtree
The attack was barely over when a legitimate-looking article began to spread. It was an interview with Crabtree, apparently a 43-year-old IT professional. "I didn't think about it. I just acted," Crabtree was quoted as saying from his hospital bed.
But the website, called thedailyaus.world -- not connected in any way to youth news website The Daily Aus -- was registered by a user based (or pretending to be based) in Iceland on Sunday. (The Daily Aus founders Sam Koslowski and Zara Seidler said their readers had been in touch to alert them to the fake news site).
However, the truth is the man who risked his life to tackle one of the gunmen and take his gun was revealed to be Ahmed Al Ahmed, a father from the Sutherland Shire, who was shot twice for his heroics.
Hedge fund manager Bill Ackman called out the misinformation, which also reveals how widespread the false account travelled. "I am told that other reports claiming the hero was a man named Edward Crabtree are false," Ackman wrote on X.
Israeli Prime Minister Benjamin Netanyahu also got it wrong, initially telling journalists it was a Jewish bystander who wrestled the gun from the gunman's hands, The Times of Israel reported.
2. Other attacks
Minutes after the first round of bullets were fired, posts began circulating about Bondi being the first of a series of co-ordinated attacks on other Eastern Suburbs locations, including nearby Dover Heights and Double Bay.
There were no witness accounts, photo evidence or verification. But posts circulated of supposed witnesses hearing gunshots and claiming to have knowledge of plans of further attacks. Another "Chanukah by the Sea" event at Dudley Page Reserve in Dover Heights went into lockdown and escalated fears and paranoia across Sydney.
The false information spread so far and so quickly the NSW Police Force had to issue a statement on social media. "There have been NO reports of any incidents at Dover Heights -- please do NOT share unconfirmed rumours," NSW police wrote.
3. IDF, Iran, Palestine ties
Before Naveed Akram's identity was verified as one of the two alleged shooters, his driver's licence was posted across social media with purported facts about his identity. It was weaponised by people on either side of Israel's war in Gaza.
Some of the most viral posts made categorically false claims that he was a former soldier in the Israeli Defence Force who had lost his mind after being stationed in Gaza. Others stated he was a Mossad agent and that this was some sort of "false-flag" attack, a term describing an incident designed to look like it was perpetrated by someone other than the person or group responsible.
There were other false claims that Akram had studied at Islamabad University and had been planted by Iran to conduct the attack.
When Akram's name was released, there were also erroneous reports about the identity of the second shooter which named an unconnected Lebanese national of Palestinian descent and which were false.
4. Wrong guy
Late on Sunday, another Sydney-based man called Naveed Akram shared two videos begging media outlets and social media sites to stop naming him connected to the attack.
This Naveed Akram is an IT specialist from Pakistan who moved to Australia in 2018 and happened to have a public Facebook and LinkedIn account which meant photos of him at the cricket and his workplace history were posted all over the internet.
The claim that it was this Akram who committed the attacks went viral after being heavily promoted by India-based accounts, including the Indian Strategic Studies Forum. It was even picked up by some traditional platforms, including US-based CBS News.
Misidentifying the perpetrator of crimes has become commonplace over the past decade since the rise of social media. Earlier this year, Sydney man Benjamin Cohen sued Seven Network after the media company's Sunrise program falsely claimed he'd murdered six people in the Bondi Junction stabbing attack in April.
5. Firework celebration
Some used the tragedy to stoke tensions across Sydney. Videos of fireworks in western Sydney circulated across X, Facebook and Reddit in the aftermath of the attack, including by right-wing content creator Drew Pavlou in a now-deleted post captioned "reports that Islamists set off celebratory fireworks in Bankstown, Western Sydney".
There were fireworks in western Sydney on Sunday night, but they had nothing to do with the horrors at Bondi. Instead, they were to celebrate Padstow's annual Carols by Candlelight event which happened to be scheduled at the same time.
The role of artificial intelligence in driving mis and disinformation will be picked apart in the days and weeks to come. But AI and social media have not covered themselves in glory in the Bondi Beach attack.
"The biggest issue is the way AI has lowered the friction to spreading and creating misinformation," Ruser said.
Kruger added: "Social media sets up an us-versus-them dynamic. In really bad moments, there's no room for nuance. It's a perfect petri dish on social media that puts people on one side or another."