“[The larger issue is] what happens when a large number of people are concentrated together in a public space and have different ideas of how we should all behave. … We see these moral panics in other crowded spaces, too.” And sometimes the policing of behavior scares away the very communities that arts organizarions are trying to reach out to. Lyn Gardner meets Kirsty Sedgman, author of The Reasonable Audience: Theatre Etiquette, Behaviour Policing and the Live Performance Experience.