Does social media lead vulnerable individuals to resort to violence? Many people believe it does. And they respond with online censorship, surveillance and counter-speech. But what do we really know about the internet as a cause, and what do we know about the impact of these reactions? All over the world, governments and internet companies are making decisions on the basis of assumptions about the causes and remedies to violent attacks. The challenge is to have analysis and responses firmly grounded. The need is for a policy that is constructed on the basis of facts and evidence, and not founded on hunches—or driven by panic and fearmongering.