Book excerpt: Procedural and moral shortcomings in both child abuse cases and the long-term deployment of undercover police officers have raised questions about the effectiveness and efficacy of intelligence work, and yet intelligence work plays an ever growing role in policing. Part of a new series on evidence-based policing, this book is the first to offer a comprehensive, fully up-to-date account of how police can--and do--use intelligence, assessing the threats and opportunities presented by new digital technology, like the widespread use of social media and the emergence of "big data," and applying both a practical and an ethical lens to police intelligence activities.