Children using the Internet could unwittingly be helping a paedophile to track them down by revealing their personal information. A first name, phone number or e-mail address, given in a chatroom or a social networking website, can seem relatively harmless, but when taken together they reveal a dangerous amount of information which could be exploited. It can be easy for predatory adults to use the Internet to build a detailed picture of potential child victims. 2nd part in the series 'Predators and Paedophiles: An Online Investigation'.