This book examines the cybersecurity phenomenon, looking at the folklore, the hype, and the behaviour of its practitioners. A central theme is that the management of cybersecurity needs to be owned by the people running the organisation, rather than by the cybersecurity team, who frequently don't have management as a core skill. In order to effect that change, managers need to have the background and detail to challenge what they are being told, enabling them to engage in a way that will result in more appropriate outcomes for the business. This book provides that background and detail. It debunks a number of cyber-myths, and calls out basic errors in the accepted thinking on cyber. The content is strongly rooted in available research and presented in an accessible manner, with a number of business-related case studies. Each chapter in the book takes a theme such as end-user behaviours and compares the available evidence with what the industry would like to have its customers believe. The conclusion is that there is definitely a problem, and we certainly need cyber defences. Just not the ones the industry is currently selling.