Hostile states and ideologically motivated groups exploit the information vacuum that follows major incidents to spread damaging disinformation, experts warn.
Falsehoods about identity, ideology and motivation spread in the aftermath of the killing of three girls at a UK dance class, much as they did following the Bondi Junction attack in April.
A teen was arrested shortly after the girls - aged six, seven and nine - were fatally stabbed at Southport in England's northeast on Monday.
Within hours, bogus claims about the suspect began appearing on social media.
In particular, it was said he was a Muslim asylum seeker who had arrived by boat months earlier. Many social media users also published an Arabic-sounding false name.
Despite the police's attempts to dispel the falsehoods, a far-right group descended on a Southport mosque on Tuesday night, leaving several police officers injured in the resulting disorder.
There has been further unrest in the UK since, including a protest outside Downing Street where attendees chanted "stop the boats" and "we want our country back".
The vacuum of information in the aftermath of major incidents provides the perfect environment for those wishing to spread disinformation, says Deakin University associate professor Josh Roose.
On the Southport attack, legal restrictions prevented the media and police from reporting the suspect's identity in the following days.
"This led to a perfect storm of events in which angry individuals are drawn into far-right narratives," Professor Roose said.
Politically motivated entities and individuals were quick to portray events according to their ideology or agenda, Monash University associate professor Emma Briant said.
"They put a spin on it, which advances whatever concerns they want to spread," Professor Briant said.
"It's trying to play on people's fears ... these kinds of reactionary framings are designed to energise people, they cause things like riots that we've seen in Southport and then lead to calls for stronger action."
Whether there is any truth in their portrayal of events is beside the point, Prof Briant said. As was the case in Southport, the damage was done before reputable information could be published.
It isn't only those with a specific ideological agenda. Foreign powers, in particular Russia, seek to benefit from discord within countries, according to Prof Briant.
"They tend to exploit incidences like this in order to drive fears, anger and tensions," she said.
"It helps to have this kind of tension in society, and it advances the interests of Russia to have their enemies destabilised and fighting each other."
Prof Roose said this was evident during the 2016 US election when Russian accounts pumped out falsehoods to drive division and influence debate.
He said Western liberal democracies are easy targets for such manipulation.
"They are exploiting ... our openness and our freedoms, because we don't regulate the internet like other countries," he said.
One of the main spreaders of falsehoods relating to the Southport attack was a little-known supposed news website called Channel3 Now.
While claiming to be US-based, a Facebook page of the same name states it is partly managed from Pakistan, while its YouTube page features dozens of Russian-language videos.
In the aftermath of the Bondi Junction attack, one of the first to push falsehoods about attacker Joel Cauchi's identity was pro-Kremlin propagandist Simeon Boikov.
Mr Boikov, who lives in Russia's consulate in Sydney and is a registered foreign agent, published false claims that Cauchi was actually a Jewish man called Benjamin Cohen.
Mr Boikov has also shared speculation about the Southport suspect's background.
Sora Park, professor of communication at the University of Canberra, said there are also those who use such incidents purely to boost their popularity and influence online.
"There's a whole group of people who are not necessarily driven by their own agenda, except for an agenda to attract more likes and clicks," Professor Park said.
"It's a lot of vanity metrics. People just feel good about getting more attention. It might be driven by a political agenda necessarily, but they just want more clicks or more popularity and the online environment encourages people to do that."
