This book is centered on Smart grids and micro-grids, as a cost-effective method of ensuring fair and equitable access to power in urban areas. It also considers scenarios where deploying smart grids can be both cost-prohibitively expensive and logistically challenging. Deploying smart microgrids instead, offers a reliable power solution but, as is the case in smart grids, a key issue is guaranteeing usability, trust, and reliability while protecting against energy theft. This book considers aspects such as state estimation, capacity planning, demand forecasting, price signals, and demand management with respect to energy theft. Straight-forward approaches to provoking energy theft on smart grids and micro-grids include mis-recordings power consumption/generation information and exposures of personally identifiable information or sensitive information. Attack models based on mis-recorded generation and/or consumption data and exposure of personally identifiable information, are also studied. In each case, countermeasures are proposed to circumvent the power theft attacks raised. Researchers in Smart Micro-grids security, cyber-physical systems, and critical infrastructure will want to purchase this book as a reference. Professionals, Researchers, Academics and students working in security general and Security of Critical Infrastructure, Privacy, and Data Sharing will also want to purchase this book as a reference.