This book discusses contemporary standards of legal safeguards in the area of bulk electronic surveillance from the perspective of the European legal model. Bulk, or untargeted, surveillance, although traditionally associated with the interception of electronic communications, is increasingly used as a convenient tool for collecting information on large groups of society. The collection of redundant information, which is intrinsic to bulk surveillance, is no longer a side effect but an important objective of the use of bulk powers. As a result, untargeted surveillance is everywhere increasingly being implemented, and without any clear link to state security or crime-fighting objectives. This work examines the origins of untargeted measures, explores their mechanics and key concepts, and defines what distinguishes them from other forms of surveillance. The various elements of the legal safeguards in place, which are fundamental to protecting individuals from the risks of abuse of power, are analysed in detail. The book discusses not only the different standards of legal safeguards, but also gives examples of their implementation in individual European countries. It also examines the relationship between the development of the global data market and untargeted surveillance powers, in particular in the context of the risks associated with algorithmic surveillance, client-side scanning, the privatisation of surveillance - or Surveillance-as-a-Service - and the increasingly widespread use of preventive content filtering mechanisms. The book will be a valuable resource for academics and researchers working in the areas of law, international relations, public policy, engineering and sociology. It will also appeal to professionals dealing with various aspects of the use of surveillance measures, such as experts, members of the legislature and law enforcement agencies.