Members of social networking websites are at grave risk of identity fraud if they list personal details such as telephone numbers, addresses and job histories, security experts warn. The alert followed a Sunday Morning Post investigation in August in which the newspaper established a fictitious identity on the popular Facebook site and invited Hongkongers to become 'friends'. Within three days, 29-year-old 'Kate Libby' - the name of a character played by Angelina Jolie in the 1995 movie Hackers - had acquired 47 'friends'. The only picture of 'Kate Libby' was of a dolphin. When users agreed to become friends, 'Kate Libby' could access personal details such as photographs, employment and education histories and, in some cases, addresses. Only three of those who signed up to be friends with the false profile queried how she knew them. Three of the profiles offered a detailed rundown of the person's identity, including the age, birthday, occupation, extensive records of work and education, telephone numbers, e-mail and home addresses. To Ka-lun, a computer security expert at the Hong Kong Computer Society, said the only additional detail needed to gain a credit card using information provided by some of the users was a Hong Kong identity card number. This could be obtained through public listings or even by going to someone's home. 'People are not alert despite the fact that they have been warned over and over again not to be so careless,' he said. 'They think it is just a social thing, and they believe it is a source they can trust, and they just give out their information.' Mr To said some young people could be manipulated by paedophiles and cautioned against posting school details on the site.