September 2016, just hours before I was due to interview the radical Islamist leader Anjem Choudary, I received a text. He asked, for reasons of propriety, could I bring someone along (a mahram)? It was a last minute request. The one friend who was willing and free had never heard of Anjem Choudary. ‘Who is he again?’ she asked. ‘I’m sure he’ll tell you,’ I said. And so he did, introducing himself with a speech about how many thousands of Twitter followers he had.
Choudary was a known social media influencer, sharing views aligned closely with those of Islamic State. Many of his supporters travelled to Syria and Iraq. Many did not come back. In the end his accounts were removed.