Over 700 arrests have been made in connection with the eruption of far-right violence this week following the killing of three young girls at a Taylor Swift-themed dance class in Southport, in the North West of England.
False claims on social media said the suspect was an asylum seeker, and that he was Muslim.
It's the worst violence in the UK in recent times, quickly spreading the length and breadth of England, fuelled by online misinformation.
So what can be done to tackle the real life harm triggered by online hate? We ask Imran Ahmed, founder of the UK Centre for Countering Digital Hate.