Social media and messaging apps play a role in the extremist “radicalisation” of individuals. Tech companies have tried to get better at identifying extremist content and taking it down, but some specialists advocate an alternative approach – to use these platforms to engage with extremists one-to-one, to confront them and talk them round. Last year, the Institute for Strategic Dialogue in London organised hundreds of conversations on Facebook messenger between activists and those expressing extreme Islamist and far-right sympathies. World Hacks has been given exclusive access to their report. This experiment raises many moral and practical questions. Do those posting extreme views online still have a right to privacy? At what point do we judge someone as suitable for this kind of intervention? And what exactly is the best way to start a conversation with an extremist? Presenter: Elizabeth Davies Producer: William Kremer Photo credit: Colin Bidwell (BBC) CORRECTION: In this programme, we say that counter-conversations were part of Facebook’s Online Civil Courage Initiative (OCCI). It was in fact a separate project, also funded by Facebook.