Facebook is to investigate how pictures posted to the social media network by Irish teenagers ended up on a pornographic website without their consent.

Parents need to have “full and frank” discussions with their children about what they are posting online and need to make sure privacy settings are activated to control who views their information, an expert in online security has warned.

The National Association of Principals and Deputy Principals (NAPD) has renewed its call for an internet safety module to be included in the second-level curriculum after the discovery of Cork teens’ Facebook pictures on a porn website.

Fantasies involving rape, paedophilia, and misogynistic violence — the website hosting photographs stolen from the Facebook profiles of young Irish women is not just a porn site, but a forum where anonymous users share pictures and swap fictitious descriptions of the vile acts they would carry out on the women depicted.