Now Bebo, the internet social network popular with children, has signed an agreement with traditional broadcasters such as the BBC to provide similar content warnings. The network had 11.4 million UK users in January, the majority in their teens.
Rachel O'Connell, Bebo's chief safety officer, told The TES the labels were part of a package of new child protection measures. They come as the networks face criticism for exposing members to risks of identity theft, cyberbullying and adult predators.
Bebo has established Safe-SocialNetworking, a site providing educational materials for teachers whose schools bar access to the Bebo site.
The big networks have also joined a new taskforce, based in the United States, which met for the first time this month to explore ways to verify the ages of members. This would limit the potential for young children to access inappropriate material, or for predators to gain their confidence by posing as someone the same age.
Photograph: Neil Turner.