The victims were teenagers when they were plied with drink and drugs and subjected to serious sexual assaults. A judge in Manchester jailed the three men for total of 37 years. Police branded them despicable, and one of the victims said she feels her life has been destroyed.
A new campaign has been launched in Liverpool to help prevent young people putting themselves in danger on-line.
Students have been the first to see a film which will be shown to teenagers around the country.
Year 10 students from Hillside High School in Liverpool have been taking part in a project being run by the Child Exploitation and On-Line Protection Centre (CEOP), the national organisation for keeping children safe on the internet.
The programme targets not just the threat of cyber bullying but also the problem of children being groomed for sex on-line by strangers.
The full scale of online child exploitation is still not known. The authorities say this makes reporting cases all the more important.