Social workers should use Facebook and Twitter to engage with people sharing extreme and violent material online, according to an expert on the far right and terrorism.
Vidhya Ramalingam said they should have the same kind of conversations on social media that a youth worker might have had with a gang on the streets.
Ms Ramalingam, who founded Moonshot CVE to tackle extremism and community violence, said new technology should be harnessed to identify people who could be at risk of committing terrorist acts in the UK or travelling overseas.
Only this week the Government published its updated "Contest" anti-terror strategy, which will see MI5 share intelligence with bodies outside the security community.
In recent years, there have been a number of high-profile terrorist attacks in Britain, including the murder of MP Jo Cox, the Westminster attacks, the Manchester bombing and the murder of Lee Rigby.
Ms Ramalingam, who was speaking at the Cheltenham Science Festival, said it was often much easier to spot radicalism online than within the community.
"Sometimes the signs are not very obvious in the world around us. We live in a real world where you can sit and touch the person next to you, but we also have an online life," she said.
"Unless they tattoo a swastika to their forehead or set up a soapbox in the street and tell us they believe in these things, it might be very difficult for us to see that in their daily lives.
"But online they could be living a completely different life. They could be standing on that soapbox posting videos glorifying Hitler.
"I believe online is not just a place where awful things happen, but it is also a place where we can do real good, there is a real opportunity there.
"The reason there is an opportunity is that people who are getting involved in these movements often leave behind a trail of clues online that let us know they are getting involved."
She said her organisation was identifying those at risk and offering them an alternative.
"We can do social work online. We can send teams of social workers into online forums, on Facebook and Twitter, to start conversations with individuals, the same kind of conversations a youth worker on the street might have had with gangs," she said.
"These sorts of methods are not too different to what has been done to deal with suicide prevention online and it also be used to tackle other types of violence, like domestic abuse, gender-based violence and human trafficking."
She said the numbers of people involved in extremism in Britain was relatively low, but the impact was very high.
"We are not talking about a mass movement here," she said.
"A very small number of individuals who have a massive ability to completely destabilise the communities around them, sometimes by killing just one person."
Professor Andrew Silke, of Cranfield University, has worked with convicted terrorists in prisons on deradicalisation programmes and said the key was changing their behaviour, citing the example of Irish republicans who moved away from violence and into politics.
"A lot of deradicalization programmes want the prisoner to not only behave, but also no longer believe in the cause. That's asking an awful lot," he said.
"The analogy I use is of football teams. Just by talking to you, could I convince you to stop supporting the football team you currently support and support instead their most extreme, direst rivals?
"Get the Manchester United fan to support Liverpool or the Arsenal fan to support Chelsea? Could I do it? So why do you think I can get a jihadi to stop believing in jihad?"
He did not support the regulation of mosques, adding: "The mosques do not present a problem; the mosques are really alert to these problems.
"That isn't where radicalisation is happening, it's happening in people's front rooms and it is happening online where people are devouring material."