Violent footage of playground fights posted on the internet site YouTube has led to a Kent head teacher considering a school ban on mobile phones.
Sites such as YouTube encourage users to put their own videos online
Neil McAree, head teacher of Temple School, Strood, took action after being alerted to the clips on the site which lets users put their own videos online.
The company that runs the YouTube site has not commented on the video footage.
But John Carr, from children's charity NCH, said allowing violent films to be put on the web was "almost incitement".
Video clips downloaded by BBC South East Today showed violent playground brawls with kicks and punches, filmed on mobile phones and often set to rap music.
One film showed teachers struggling to break up a fight.
Charity technology consultant Mr Carr said: "The fact that websites like YouTube allow videos of this kind to be posted is almost an incitement for youngsters to go out and beat somebody up just so they can film it, put it up on the web and get their five minutes of fame.
"It's completely unacceptable."
Mr McAree said: "We have dealt with the episode that we've learnt about today and I believe we dealt with it very promptly.
"Parents have been spoken to and the matter will be seen through to the end.
"I hope other schools don't experience this problem and I certainly hope the young people involved learn the lesson of the inappropriateness of what they've done."