The outrage comes after rival networking site Bebo adopted the button that allows users to contact trained child protection officers and also provides details of local police and links to 10 other sources of help.
Popular social networking websites Facebook and MySpace have come under fire for failing to introduce a help button for children being bullied online.
Jim Gamble, from the Child Exploitation and Online Protection Centre (Ceop), criticised MySpace and Facebook for not following the same example of Bebo.
He said there was “no legitimate reason” for not doing so and that social networking sites were raking in money through advertising by attracting children and teenagers to join.
“We applaud that but do not forget while you do that there is a responsibility, a duty of care, to the young and the vulnerable,” The BBC quoted him as saying.