Hundreds of people will blow the dust off five missing person cold cases with the aim of generating fresh leads for police in a nationwide "hackathon".
The event being staged in all capital cities as well as remotely on Friday involves more than 650 people with high-level open intelligence skills to those with a handy knack for scrolling Facebook comments.
Some come with their own software, others use training provided in the event lead-up.
Event founder Linda Cavanagh said a previous event in 2020 generated about 40 new leads across 12 cases.
"We've had had people finding comments on Airbnb posts, we've had drone footage, imagery as well," she told AAP.
"The majority does come from (the missing person's) digital footprint - the minute you touch the internet, you leave a trace."
Narrowing the number of cases to five will hopefully encourage deeper dives and provide the crucial information detectives need to unlock each cold case.
A new challenge will be a person who disappeared at sea while on their own boat, likely leading to people trawling for geoimagery in the relevant timeframe.
Ms Cavanagh said the information uncovered often become a telling moment for participants themselves.
"They'll say 'I've just pulled together the narrative on someone's life - what could someone find on me?'
"It's a bit eye-opening from a cyber perspective."
The event is also an opportunity to recast the term hacker, so often portrayed by media as a shadowy figure in a hoodie looking at dark screens.
"This shines a light on ethical hackers - they're there to do good," Ms Cavanagh said.
"Often they do vulnerability research and find potential intrusion points."
Cybersecurity expert Jason Murrell agrees.
"The event highlights cyber security's critical role in protecting our nation, and it's a powerful reminder of what we can achieve when we come together for a common cause," the Australian Cyber Network chair said.
The event runs for five hours.
