A failure by governments to crackdown on social media in the technology's infancy may have contributed to young people being radicalised online, security experts say, as Australia's terror threat level was raised.
ASIO increased the terror threat level from "possible" to "probable" after the intelligence agency's chief revealed eight attacks or disruptions that involved alleged terrorism had been investigated in the past four months.
The agency's director-general Mike Burgess said the decision to heighten the threat level was not due to a specific incident and while tensions in the Middle East meant strains in Australia, they had not directly contributed to the increase.
Mr Burgess also pointed to a large number of young people being radicalised online as a major point of concern, with half of ASIO's cases involving minors.
He said COVID lockdowns had exacerbated the amount of time young people spent online.
"It is a concern how social media can grab people quickly, the internet can grab people quickly and hurt young brains which are not fully formed," he told ABC TV.
"You could fall down a rabbit hole of hate quickly."
Australian Strategic Policy Institute executive director Justin Bassi said governments not enforcing social media in its early years had contributed to platforms not being regulated, allowing for the radicalisation to more easily occur.
"These issues of people being angry, people being feeling disaffected, and people having a issue ... have always been there. The advancement in technology and use of social media has a huge amplifying effect," he told ABC Radio on Tuesday.
"When social media was being developed, mistakes were made by democracies by not regulating early enough, not baking in security.
"The question though now is how do you get that back? We're so far down the line, people rely on the internet, rely on social media for their lives and livelihoods."
Lone-wolf terror attacks with little warning and simple weapons such as knives were a major threat, the spy chief said.
Of the eight cases since April, only two were known to police or intelligence services, he said.
"People will go to violence with no warning," he said.
"(The cases) are symptomatic of what we are seeing in society with increased temperature, violence is more permissible."
One person investigated had latched onto the extreme left-wing Antifa but had neo-Nazism in a manifesto, Mr Burgess revealed.
"That defies logic, I would suggest they are not really hooked on either of those ideologies, they are hooked on the violence element," he said.
Opposition home affairs spokesman James Paterson said the decision by ASIO to raise the threat level was sobering, but not surprising.
"This is a real concern, and a lot of it is happening much faster. It's happening online, as people are exposed to increasingly extreme content that can radicalise them very quickly," he told ABC Radio..
"Regardless of whatever your particular political motivation or ideology is, anyone who thinks that violence is an appropriate way to achieve those ends is breaking the law and should be harshly dealt with."
