He grabs the other boy, picks him up with two hands and throws him head-first on to the concrete. A "crack" sounds as the 12-year-old's ankle connects with a timber bench. The Sydney school involved, Chifley College's Dunheved Campus at St Marys North, has suspended both students and called police after footage of the fight, which took place on school grounds about 10.30am yesterday, was aired on a television station. In three days' time it is the National Day of Action Against Bullying and Violence. The video, meanwhile, was posted on Facebook and was going viral early today. It was removed by Facebook and YouTube just before 3pm but is still available on other sites, in a modified format. Commenters on Facebook numbered in their hundreds and sided overwhelmingly with the older boy.

"I think it's great that he's standing up for himself. It just sucks that schools don't even try and stop bullying," said one. "This kid is my hero," said another. One said they knew the older boy personally and that he had been a victim for some time. "I find it disgusting that he was suspended for it," they said. "I understand why he was but he still shouldn't [have] been." Their triumphant response to the older boy's retaliation surprised seasoned experts. "Our first reaction is obviously one of distress. That is a very distressing video for a number of reasons," John Dalgleish, head of research at Kids Helpline and Boys Town, says.

"Often children ... will blame themselves for actions done towards them. One of the first things we do at Kids Helpline is talk that through with young people and give a very strong message saying no child ever deserves or should be subject to bullying." It is understood the Year 10 student is a victim of repeated bullying at Chifley College's Dunheved Campus, a middle school in a disadvantaged part of western Sydney. But police and bullying experts are concerned by the video's publication on Facebook and the overwhelmingly positive reaction to the older boy's retaliation against his attacker. "We don't believe that violence is ever the answer," Mr Dalgleish says. "We believe there are other ways that children can manage this." Just one student out of the five observable, an older girl, steps in to stop the situation escalating.

She physically stops a friend of the younger boy from going after the older boy, telling him to "back off". "The longer term way is about developing better relationships between kids in the school, that will then empower young people to not be passive bystanders when these acts occur but to stand up and say 'this is wrong'," Mr Dalgleish says. "The short term solution is to have individual counselling with each of the children." St Marys Police duty officer Inspector Jason Green said posting the video had the effect of glorifying violence in schools. "...Whether it causes other incidents or not I don't know but it seems to be a trend of late," Inspector Green said.

"It may incite other violence but that's something that we can't comment on." Police are trying today to speak to the parents of both boys. As to what punishment would be handed out, Inspector Green said any action would be in accordance with "juvenile procedures". The school would also deal with the boys. "But we have to deal with them as there still is some criminality with regards to their actions," he said.

Social media pundits said the proliferation of mobile phone video would expose the magnitude and reach of cyber bullying. "The education system needs to stay up to speed on how they deal with these issues," says Julian Cole, digital strategist at social media agency The Conscience Organisation. He said that although there had been support for cyber bullying from government and online organisations, it was only "when these grass roots movements occur when we see the real change occur, with governments giving more support to the issue". Loading "Where we used to get people to sign petitions people are now joining Facebook Pages/Groups to show their support for these issues," Mr Cole says.

Follow these reporters on Twitter @geerob & @bengrubb