From a lab on the grounds of Melbourne University, computer scientist Mahtab Mirmomeni has been leading a team of five in a fight against a hidden enemy: child sex traffickers.
Their aim was to create a website where victims of trafficking could access information, services and help quickly and without detection by those who have detained them.
While non-governmental organisations across the globe struggle to agree on the figures, current estimates suggest around 1.2 million children are trafficked worldwide every year.
Research compiled by the University of Queensland puts the number of trafficking victims of any age in Australia at less than 100 per year, although that figure refers only to reported cases.
There's a touch of deliberate irony in using the internet to help victims, says Ms Mirmomeni, given websites are often used to lure women and children into servitude.
"Three out of four of these girls were trafficked online," she explains. "This project aimed to use the internet in the opposite direction."
Their task formed part of a global challenge initiated by anti-trafficking organisations and supported by Microsoft.
Yasmin Vafa of the Human Rights Project for Girls in Washington D.C. says the idea of creating an online resource to help victims came out of years of working with survivors of trafficking and at-risk youth in the United States.
“We have become increasingly aware of and concerned with the role the internet was playing in the exploitation and marketing of children online for sex,” she says.
“So as an organisation, we had been playing and grappling with the idea of… how we might use the internet to protect these children and liberate these children."
The web is also commonly available to girls even in marginalised situations, she says. “They're still high-level consumers of internet technology.”
“The idea was to have a one-stop shop that would give the girls the resources, information and access to support to help them exit the life and seek the freedom they need.”
But the policy and advocate workers in Ms Vafa's organisation had “zero experience with technology,” so they teamed up with Microsoft to assess the requirements.
Microsoft in turn set the task as a “hackathon” challenge – a women-only crowdsourcing event designed to encourage up-and-coming computer programmers in universities around the world to push their skills.
Rane Johnson, a research director for Microsoft, says the decision to target human trafficking as one aspect of the hackathon was intended to inspire women in technology as well as work towards solutions for a critical problem.
"The number one focus, really, is how do we encourage more women who want to be a computer scientist?" she says.
The challenge allowed young programmers to think creatively to get information to women whose movements might be monitored or restricted.
For participants, mobile phone apps were a popular choice.
"A lot of them wanted to go towards phone apps because most young victims aren't going to have access to a computer, but they will have access to a smartphone," says Ms Johnson.
In some cases, teams submitted apps that contained valuable information in clever disguises, such as a 'princess' game.
Mahtab Mirmomeni says the unusual nature of the task also helped her team stretch their skills in unexpected ways, as they were forced to consider complex problems and solutions.
Some, like the problem of hiding a digital footprint, had relatively simple solutions.
"One of the requirements is the website has to be hidden from the traffickers," she says. "Their browsing history would not be saved on the computer."
"Another problem was that we found out the girls don't even know where they are."
A geo-locator button – similar to GPS – could be added to show a victim a map of her own location.
But the more challenging problems, says Yasmin Vafa, are related to the complex social issues that victims often face. “One of the things that we've seen in our work with survivors is that has to be on her own time, and on her own terms.”
“It's very rare that you'll have a girl come in and be immediately ready to exit that kind of lifestyle."
"Our vision was just to have a website there as a resource so that girls could come to it as many times as they needed and... at least know what services are available."
Although the website will initially be targeted at US victims, it's a model that could be adapted to suit other regions, says Ms Vafa.
The internet and sex trafficking
As the internet has grown and become a more sophisticated tool, sex traffickers have adapted their methods to use it to their advantage.
Activists at international anti-trafficking organisation Polaris Project have called it the “number one platform for pimps, traffickers and johns” in the US.
Websites such as largely unregulated virtual message board Craiglist have been found to be used as a mechanism for selling sex, sometimes illegally.
Unlike prostitution, trafficking involves the soliciting of sexual services under force or coercion. Often, it's the most vulnerable girls and women who end up in the situation.
That includes a “vast number” of children and runaway youth in the US, says Ms Vafa.
View more about the Hackathon project here.