Cassidy Wolf
Cassidy Wolf: beauty queen was target of online spying and extortion (Twitter)

Experts have warned of the dangers of online 'sextortion', after a 19-year-old classmate of Miss Teen USA Cassidy Wolf was arrested for allegedly hacking into her computer, photographing her naked with its webcam, and attempting to blackmail her into performing sex acts for him.

Jared Abrahams admitted to prosecutors that he had as many as 150 'slave' computers under his control, taking pictures of women undressing and threatening to make them public unless they performed for him.

He reportedly anonymously emailed Wolf with pictures of her naked, and wrote that unless she complied with his wishes: "your dream of being a model will be transformed into a pornstar (sic)."

Speaking on The Today Show Wolf, who is now a college freshman, said that she had 'mixed emotions' about Abrahams' arrest.

"I don't think he realised the consequences [to the things] that he's done. He terrorised me and many other girls for so long," she said.

Experts said that many young people are unaware of the dangers they face online from hackers using sophistcated technology to harness their computers.

They warn that many use remote administration tools (RATS) to take control of webcams without the LED light that indicates that it is active turning on. They are also able to access microphones and steal private information from hijacked computers.

Mathew J. Schwartz, a cybersecurity expert with InformationWeek, said there are entire forums to help people gain access to sextortion photos.

"There's a subculture that thrives on trading stolen webcam images," he wrote. "Perusing a section of devoted to RATs produces a wealth of images labeled as 'hot female slaves' and 'ugly slaves."

Recently, the UK's Child Exploitation and Online Protection Centre said that hundreds of children were being blackmailed into performing sex acts online, with seven victims committing suicide.

Online blackmail "is a continuation of what was already happening for a long time in the terrestrial world," Laura Huey, a cyberpolicing expert at the University of Western Ontario told the AP.

"This is an especially dark area because sexual offenses go unreported because victims don't report. They're intimidated for a variety of reasons. They feel ashamed and scared, and, particularly with young children, they may not fully understand the nature of their exploitation," she said.

Cybersecurity experts say that a measure as simple as putting a piece of tape over a webcam when it is not in use can prevent hackers violating their privacy.

They also advocated keeping security software up-to-date.

"Young people must remember that the online world is the real world. Pictures can be distributed to thousands of people in seconds and can never be fully deleted," said John Cameron, the head of the NSPCC helpline. "We need to educate young people but also reassure them that no matter what threats people make to them over the internet, they can be stopped and the crime they are committing is very serious and can result in a lengthy jail sentence."

Wolf has herself toured schools in the US to warn children of the dangers of online sextortion.

"You just need to be so extremely careful with what you do online nowadays because you never know what people can be doing to you online," she told Fox.

Hacker Abrahams was released on a $50,000 (£31,000) bond and fitted with an electronic tag. He is only permitted to use his computer for school work, and will have special software fitted to monitor its use.