In recent years, speech inciting hatred, peddling dissemination, and encouraging self-harm has proliferated on social-media platforms like Facebook and Twitter, prompting calls for regulation to force platforms to tackle these challenges more aggressively. One of the most ambitious proposals is the UK’s own Online Safety Bill, which looks likely to be passed (in some form) by the current government and will grant Ofcom substantial new powers over social media. Yet the Bill is highly controversial, prompting concerns over censorship of legitimate speech. What will this regulatory regime look like in practice? Will it effectively prevent harm? And is there merit to the concern that it will undermine free speech? To confront these issues and more, we are joined by leading experts and practitioners from academia, civil society, and Ofcom itself.