Experts blame ‘hateful soup’ of social media content as MI5 boss points to threefold increase in under-18s being investigated

Teenagers as young as 13 are coming under suspicion of engaging in terrorism after being exposed to a toxic cocktail of easily accessible far-right extremism online, experts have warned.

Insiders describe “a horrible hateful soup” of social media content where children can “pick and mix” terrorist narratives, including the Terrorgram network – recently banned in the UK – of white supremacist channels on Telegram.