This book is one of the most comprehensive explorations of how biometric systems are being used round the world and the laws (or lack of) which prescribe this. Whilst it does not profess to be exhaustive, it gives a snapshot of the global state of biometric surveillance in 2023. It is aimed at anyone wanting to better understand what biometric mass surveillance is, why we should care, and what can give us hope in the face of powerful state and private actors