Facebook is among 140 websites that will install 'panic' buttons on their site, which allow children to report inappropriate content or acts of cyberbullying. (UPDATED: Facebook and the other web companies will not be installing panic buttons after it was revealed the button is not currently required under a voluntary internet code.)

The button is part of new voluntary code for internet safety, which the social network has signed up to. Clinical psychologist Tanya Byron, who advises the government on online safety, created the guidelines, which are expected to be officially launched tomorrow.

The UK Council for Child Internet Safety (UKCCIS) will be responsible for fully detailing the internet safety standards, before publishing them next summer.

Other measures include providing a 'safe search' option and parental controls that allow adults to restrict access to pages on a participating website that are offensive or where cyberbullying has been experienced.

Bebo which was recently revealed as the worst social network for cyberbullying, was the first to offer users a panic button.

The 'CEOP Report' button was created in conjunction with the Child Exploitation and Online Protection (CEOP) Centre, and can be found on every profile.

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