Online harm is one of the newest frontiers in the trend towards greater regulation of online content. This stems from the realization in recent years that content on the internet can cause real harm and that the challenge is global. Posts promoting extremism have been linked to acts of terror, campaigns of disinformation and “fake news” have dogged democratic elections and charities and governments have drawn attention to the horrifying volume of child sexual abuse imagery circulated online. Harmful online content and activity include cyberbullying, racism, misogynistic abuse, pornography, and material promoting violence and self-harm.