In a world that wasn't always kind, Hayley Jordan's little house was her refuge. Pregnant at 15 after an unsettled childhood, by the age of 21, she had found peace in a red-brick terrace with a "posh front door" in a quiet West London cul-de-sac. Framed photographs and bric-a-brac lined the neat living room, while scores of handbags hung in a bedroom, remnants of a social life that Hayley, by then an unemployed mother of two, could only dream about.

While caring for sons Daniel, 4, and Harvey, 21 months, Hayley was planning a future as a beautician and flooring friends with her comic skills. "She'd make anyone laugh," says her sister Sabrina. "She wouldn't have it if anybody was upset. She'd always do her best to make them happy." Talented singer Hayley "did a wicked Celine Dion", remembers Sabrina. "She was going to go on Stars In Their Eyes [a celebrity impersonation talent show]." Hayley was going to do lots of things before her world took a violent and ultimately, public, fall - right in the place she felt safest.

In August 2005, Hayley was invited, with her boys, to a barbecue at the house that backed onto her garden.

Afterwards, her memories of the event were fuzzy. She had drunk way too much wine and suffered from memory loss. Among the few mental snapshots were other parents and children, and a feeling of nausea so bad that she had to leave the barbecue.

The host of the party, Adam Sorrenti, took Hayley home. He was joined there by Kyle Scott and David Hedges. In her next conscious moment, Hayley was on her lounge room floor. "She was absolutely horrified," says Sabrina. "She knew something had happened, but she couldn't put her finger on what."

Two months later, Sabrina was called by the welfare authorities. "They said that a tape, or DVD, had emerged which featured my sister being raped by three men with the children watching in the room," she recounts, quietly.

As Hayley lay unconscious on her black leather sofa, Scott, now 21, Sorrenti, now 19, and Hedges, now 22, had stripped the young mother, sexually assaulted her with a TV remote control, and videoed the attack on a mobile phone. In the background, Hayley's little boy Daniel can be heard crying, "No, don't do that, don't do that to my mummy!"

No data exists in Australia on the incidence of videotaped sex assaults, but a spate of recent high-profile cases has cast the spotlight on a terrifying new phenomenon. "The core of it is the assault of a human being, most often a woman, by a person, most often a boy, filmed by an accomplice, most often a boy, and then that footage is uploaded onto YouTube," says adolescent psychologist Michael Carr-Gregg.

Karen Willis, manager of the NSW Rape Crisis Centre, explains, "One of the impacts of sexual assault is a feeling that everybody knows. If it's filmed, it adds to that because it's not only the person who did it, but who knows who they've shown that to?" If the film is posted on the internet, the humiliation is multiplied. "Every person who looks at them and smiles or nods, [the victim is thinking] has that person been watching what happened to me?"

One of the most disturbing filmed attacks has become known simply as the "Werribee DVD". Last year, 11 youths pleaded guilty to making a film that showed them inflicting gross and degrading abuse on a 17-year-old girl on the western fringes of Melbourne. The film, excerpts of which were aired on a national current affairs TV show, shows the boys urinating and spitting on the girl, poking her with sticks and setting fire to her hair, before throwing her clothes in a river and up trees. They forced the girl, who has a learning disability, to perform sex acts and wrote their film's title, C***, The Movie, across her breasts. On the video, which was sold at Melbourne schools for $5, one boy is heard to say, "Fuck, she's the ugliest thing I've ever seen.