Across France and much of Europe, a new breed of online cults and extremist communities is on the rise — one that isn’t recruiting door-to-door but algorithm-to-algorithm. Social media platforms and messaging apps are helping fringe movements, conspiracy networks, and radical groups reach and radicalize young people in ways that traditional laws weren’t built to handle. Governments are scrambling to catch up, crafting new regulations and digital oversight mechanisms — from France’s long-standing anti-sect agency, MIVILUDES, charged with monitoring cultic abuses, to broader EU content-regulation frameworks like the Digital Services Act aimed at forcing platforms to take responsibility for harmful content online. At the same time, policymakers in Paris are debating fresh restrictions on youth access to social media to stem exposure to dangerous or manipulative material. But the balance is delicate: how do democracies protect citizens — especially the vulnerable — without stifling free expression or inadvertently legitimizing extremist narratives?