Introduction

This chapter looks at a number of different contexts in which surveillance is practised, and considers some of the different ethical issues that surveillance raises in each case. It also looks at the more philosophical issues pertaining to surveillance, and examines a number of different contexts in which surveillance occurs. The chapter describes at international espionage, which has received considerable attention since the revelations of Edward Snowden in 2013, but was already subject to ethical investigation prior to this. It asks whether it is even meaningful to apply ethics to the activity of espionage, and then consider different ethical approaches that have been suggested, concentrating on the use of the "just war" tradition as an ethical model. The chapter considers mass surveillance of a population, and the possibility of justifying this by appealing to finding trends in big data. It looks at the challenges posed by encryption and the collection of metadata rather than the content of communications.