However shocking the murder of 17-year-old Ashleigh Hall, there was nothing too surprising about the way Peter Chapman was able to "groom" his victim online - posing as a teenager on Facebook and winning her trust before finally arranging to meet.
Last year the Child Exploitation and Online Protection Centre (CEOP) received well over 1,000 reports from the public concerning allegations of grooming. "The internet hasn't created sex offenders, but it's changed the way they operate," says CEOP's spokesperson. "Twenty years ago these people would have hung around the school gates - now they use those online environments which young people enjoy."
Schools have a legal duty of care to try to protect pupils, not just from chatroom predators, but also from other online risks such as cyber- bullying, fraud and pornography. It's a tough ask. Most schools monitor internet use and rely on filters to block certain sites, but censorship alone isn't enough.
"Security systems are a useful tool," says CEOP. "But the really important thing is that young people learn how to behave responsibly online."
At Westminster Cathedral Primary School in Pimlico, London, children as young as five are taught the basic rules of e-safety: never give out personal information on a public site; always contact an adult if you have concerns.
"It's important to start young so that good habits are ingrained," says teacher Amy Chapman. "And you have to teach e-safety through regular schemes of work. It can't just be a one-off."
Once children begin to use the internet socially, schools can advise them on how to use networking sites and chatrooms safely. This means explaining the importance of privacy settings and buddy lists, and encouraging them to use sites that are age-specific, or that feature a means to report suspicious behaviour. With older pupils, it's important to stress the risks of posting unsuitable images online and to make children aware of the strategies that predators may use - such as claiming to like exactly the same music or football team before steering things in a sexual direction or asking to meet.
It is also important that schools work closely with parents, to ensure a consistent message. "We hold regular e-safety sessions for families," says Ms Chapman. "Most of the activities that put children at risk will probably happen at home, and parents can sometimes lack the confidence or know-how to set boundaries."
The good news for schools and parents is that there is a wealth of resources right across the age range. Organisations such as CEOP and Becta, the Government communications and technology agency, can offer advice on accredited internet service providers, or arrange for volunteers to visit schools to deliver e-safety workshops.
"The more high profile you make the e-safety issue within school the better," says Ms Chapman. "Because the more you talk about it, the easier it will be for a child to come forward if they have a concern."