I posed as a girl of 14 online. What followed will sicken you 
 
 
 
 Even after 15 years in child protection, I was shocked by what I encountered when I spent just five minutes on a social networking site posing as a 14-year-old girl. Within 90 seconds, a middle-aged man wanted to perform a sex act in front of me. 
 
 I was deluged by strangers asking stomach-churning questions about my sexual experience. I was pressured to meet men with whom I'd never before communicated. 
 
 So I wasn't surprised that a vulnerable teenager, Ashleigh Hall, was groomed on Facebook before being brutally raped and killed. 
 
 Paedophiles' playground: Child sex offenders actively search for young girls on social networking sites who will fall prey to their false charms (posed by model) 
 
 Anyone who knows what an adventure playground social networking sites offer paedophiles would only be surprised that such tragedies don't occur more often. 
 
 For the internet is full of people with sexually deviant desires - the level of danger goes way beyond even the most worried parent's imagination. 
 
 Child sex offenders existed before the internet, but with the inviting, anonymous environment such sites provide, they have greater access and opportunity, which they exploit all too readily. 
 
 For these depraved men are not just lurking online hoping youngsters will find them; they are actively searching for young girls who will fall prey to their false charms, as I discovered when I set out to investigate this dangerous environment. 
 
 
 
 I am vastly experienced in the field - I was a police detective specialising in major crime and worked on some of the biggest murder and paedophile investigations in the country, before gaining a masters in criminology and setting up a child protection consultancy. 
 
 I knew the enormity of the problem, but I wanted to make public how easy it is for paedophiles to approach youngsters online. 
 
 So, I created a fake profile and photograph portraying me as a pretty, slim, 5ft 2in brunette who liked music and dance. 
 
 Within five minutes of the profile going live on one of the biggest social networking sites, messages from men poured in. The first three who approached me were aged between 20 and 40. Each asked 'A, S, L?' - teen text speak for: 'What is your age, sex and location?' 
 
 These hunters know their prey chillingly well; using teenage language nourishes girls' trust. 
 
 They could have easily turned themselves into teenagers - as I had done - but many make little effort to disguise themselves because they think they'll get away with it. And many do. 
 
 After I typed back messages saying '14, female, London', the replies flew in: one man wanted to meet up immediately and asked what I liked doing or if I'd enjoy a trip to the cinema. Another promptly asked: 'Are you a virgin?' 
 
 Their audacity was shocking - they made no attempt to hide their intentions, despite the fact that having sex with a 14-year-old girl is classed as rape. They aren't afraid to be up front because - nauseatingly - they have found this approach to be effective. 
 
 Clearly, enough girls are intrigued by these crass invitations to make it a worthwhile strategy. 
 
 Some men approached me more slowly, building up rapport through normal conversation - all in abbreviated language or child-like spelling. Then they started springing crude questions, such as: 'Had I had sex? Who with? Did I like it?' 
 
 Some would make relentless and disturbing requests: would I perform sex acts for them on a webcam? Could they perform sex acts for me? 
 
 Gruesome though it is to hear, the question 'Have you ever touched yourself?' is frequently fired off to young girls. 
 
 Some men checked to see if I really was a young girl by asking innocent questions about my likes and dislikes, such as my hobbies and where I went to school. 
 
 Then, once they'd had the responses that showed I was young, they followed up with crude sexual requests or the constant chat and attention that experienced abusers use to groom girls. 
 
 And I had been online for only an hour. The scale of potential abuse is mind-blowing. Especially if, like me, you're a parent. 
 
 Our children might be savvy and aware, but, by nature, they are trustworthy and believing. Meanwhile, online paedophiles are devious, clever, calculating and manipulative. 
 
 They use photographs of other people - easily found and copied off the internet - if they want to make themselves look younger or more attractive, just like Ashleigh Hall's murderer, Peter Chapman. 
 
 And they constantly develop strategies to combat children's wariness. One new tactic is introducing victims to another teenager, who they say is a friend. 
 
 In fact, the other girl's profile is fake, created by the abuser to allay concerns. The victim believes that the stranger must be trustworthy because he has other young friends. 
 
 The 'other girl' will tell them: 'I was a bit scared, too, when I started speaking to him, but he's a really nice man, very genuine; we've met and he is who he says he is.' 
 
 Other abusers use a fake girl to encourage the victim to engage in sexual behaviour, saying such things as: 'He gave me a kiss the other day and it was nice' or 'My first sex was with him and he's careful and delicate.' 
 
 It's horrifying, yet this is happening to teenagers right now across the internet. 
 
 Once we taught children that strangers held the greatest danger, but in the world of instant intimacy that is cyberspace, teenagers don't consider these men to be strangers; they think they are friends. 
 
 And the stereotypical image of the weirdo couldn't be more misleading: these men appear responsible and respectable. One thing they have in common is that they are confident and able when dealing with children and young people. 
 
 Parents need to realise that these people are clever at appearing normal. They don't stand out in a crowd; they look no different to you or me. 
 
 
 
 The Government must provide police forces throughout Britain with the resources for covert policing, so they can lure men with fake teenage profiles before they ruin the lives of real children 
 
 They hold down jobs and are able to perpetrate abuse by hiding behind the internet for anonymity. 
 
 I know, because I have met some of the most dangerous sex offenders in the country in prisons. 
 
 The problem is that they can be caught far too late - like 33-year-old serial rapist and killer Peter Chapman. 
 
 What happened to Ashleigh Hall is desperately sad, but not surprising, given the proliferation of paedophiles online and the fact that 25 per cent of girls and 14 per cent of boys who make contact with someone online will go on to meet them in person. 
 
 That is why the policing of social networking sites must be changed radically. 
 
 I have followed a Metropolitan police paedophile unit that uses a covert approach to ensnare online abusers and arrest them. 
 
 It was incredibly effective, putting ten men in jail, but it is not practised enough. Tragically, the common police approach is reactive: finding and arresting abusers once they have been reported. By then the damage has been done. 
 
 What is needed is a pro-active approach. The Government must provide police forces throughout Britain with the resources for covert policing, so they can lure men with fake teenage profiles before they ruin the lives of real children. The hunters must become the hunted. 
 
 At present, these monsters wander the internet without fear or caution - evident by the onslaught of inappropriate messages I received when I put my fake profile online. 
 
 For what is most shocking about my investigation is not only the number of predators waiting to pounce, but also the lack of policing. 
 
 Those men who approached me are probably still there, waiting for young girls. In fact, they may have already found and preyed on many more. 
 
 But because we don't have proactive policing, they will remain at large until someone they abuse reports them. As a parent, I don't consider that acceptable. 
 
 Yes, my 14-year-old daughter uses Facebook, but with stringent privacy settings and a maximum of 30 friends, all of whom she must know genuinely - and I am one of them. 
 
 What happened to Ashleigh must never happen to another child. We need to turn around the online environment by targeting sex offenders before they target young girls. 
 
 Ultimately, it's up to all of us - parents, teachers, police and internet companies - to educate and protect our children. Otherwise there are going to be many more Ashleighs. 
 
 • Interview: Laura Topham 
 
 CLARIFICATION ||||| Facebook has threatened to sue the Daily Mail for damages after the paper wrongly claimed in a piece published on Wednesday that 14-year-old girls who create a profile on the social networking site could be approached "within seconds" by older men who "wanted to perform a sex act" in front of them. 
 
 The paper apologised in print today and online yesterday for the error, which the author of the piece, Mark Williams-Thomas, insisted had been introduced at the paper despite being told it was wrong. Williams-Thomas, a former policeman who now works as a criminologist, subsequently explained: "At 19.48 hours on Tuesday 9th March I sent amended copy to the interviewing journalist at the Daily Mail in which I had made small but significant changes to the copy she had sent to me which I read at 19.21, including removing the word Facebook and replacing it with 'well known social networking site'. I made it very clear to the journalist and her alone that the changes I had made were necessary before publication. It is clear that the changes were not made... At no stage prior to publication did I have any communication with any editors at the Daily Mail." 
 
 Williams-Thomas insists that he was not using Facebook but had been using another, unspecified social network. 
 
 But the giant social networking site, which has 23 million users in the UK alone, said that although the Mail has changed the headline of the article online – so that it now reads "I posed as a girl of 14 online. What followed will sicken you" – it had not at first changed the page title of the article online, used by internet search engines to index content, nor the URL of the piece, which is also a factor in search-engine indexing. 
 
 At 10am today the title still read "I posed as a girl of 14 on Facebook. What followed will sicken you" while the URL contained the text "i-posed-girl-14-facebook-what-followed-sicken-you". The title and URL were, however, amended before noon. 
 
 A UK spokeswoman for Facebook said the company was still considering legal action and looking at the "brand damage that has been done". 
 
 Charles Garside, assistant editor of the Daily Mail, said that the apology had been produced in consultation with Facebook, and that representatives of the paper and Facebook would be meeting today. The changes to the URL and page title were "a technical matter", he said, adding: "We are removing elements of that". 
 
 The incorrect naming of Facebook is understood to be blamed on "a matter of miscommunication". 
 
 Facebook staff claimed that attempts to add a comment to the piece, as readers are able to do, were repeatedly blocked by the Daily Mail. 
 
 The company is concerned that the article may have done permanent harm to its reputation in the UK. "If you were a Middle England reader and your child was on Facebook, this sort of thing would have a very serious effect on what you thought of us," said the Facebook spokeswoman. 
 
 Tensions over Facebook's position in the UK as a popular site among people of all ages, allowing them to contact each other, have been magnified in the past week after Peter Chapman was convicted of murdering Ashleigh Hall, a 17-year-old girl who thought that Chapman, 33, was also a teenager. Chapman had got in touch with Hall via Facebook, leading to criticisms from some senior police officers over the measures that the site takes to protect susceptible individuals . 
 
 But the Daily Mail piece, which carried Williams-Thomas's byline, suggested that anyone who signed up as a 14-year-old girl would be approached "within minutes of the profile going up". The piece also said that "messages from men poured in" and that "the first three who approached me were aged between 20 and 40". 
 
 However, Williams-Thomas and his agent, Sylvia Tidy-Harris, both insisted on their Twitter feeds that he had not used Facebook for the Mail article. 
 
 It "was on another well-known SNS [social networking service], not Facebook", said Tidy-Harris, echoing Williams-Thomas. 
 
 Tidy-Harris said that yesterday had "Been a hellishly tough day trying to juggle @mwilliamsthomas misquote in daily mail along with meetings and literally 100ks of calls/emails". 
 
 At Facebook, the anger at the misrepresentation was magnified because, they say, they were initially unable to get any response from the paper to their appeals for corrections. 
 
 "The people at Facebook in the US were reading this and knew at once that it couldn't have been our platform," said the Facebook UK spokeswoman. "We have made Facebook much more favourable to the safety of minors – minors under 18 cannot receive messages from somebody over 18." 
 
 That means it would be impossible for the scenario described by Williams-Thomas to happen on Facebook. 
 
 Facebook's representatives said that they tried to get a response from the Mail throughout Wednesday without success, and that attempts by people at its PR agency to post comments on the piece with clarifying text failed. The Mail uses moderators who on that story approved comments before they could appear. By this morning the article had 380 comments. 
 
 Williams-Thomas has not responded to requests to specify which social networking service he was using by the time of publication. 
 
 • To contact the MediaGuardian news desk email editor@mediaguardian.co.uk or phone 020 3353 3857. For all other inquiries please call the main Guardian switchboard on 020 3353 2000. 
 
 • If you are writing a comment for publication, please mark clearly "for publication". 
 
 • This article was amended on Friday 12 March to clarify that Mark Williams-Thomas says he had no contact with "editors at the Daily Mail" and to include his expanded clarification of the chain of events from his point of view.
– Posing as a 14-year-old girl on Facebook, a Daily Mail reporter was bombarded by messages from 20- to 40-year-old men wanting "to perform a sex act"—only it was really another social networking site, and Facebook is livid and threatening to sue over the misreported story. The author of the item, which appeared yesterday, said he was on another site and that editors added the mention against his wishes. Fine, says Facebook, but the paper was slow to respond and the damage is done. The Facebook mention is now out of the title, URL, and page title of the article, though that is a recent development. In fact, intrepid surfers can still find “Facebook” in the headline through a Google search. A Facebook UK spokeswoman tells the Guardian the company is evaluating what “brand damage has been done," and stresses that the scenario reported is impossible. “Minors under 18 cannot receive messages from somebody over 18.”