The issue of internet radicalisation has been taken up to the level of G7 – the governments of the US, UK, Germany, France, Italy, Canada and Japan — after warnings by counter-terrorism officials of an ongoing Islamist offensive. Earlier this week the head of MI5, Andrew Parker, spoke of Britain facing unrelenting attacks at an unprecedented scale.

This was partly fuelled, he said, by extremists finding motivation and material online, from indoctrination to bomb-making tutorials, as well as explosives available for purchase.