Digitisation has provided intelligence agencies with the capabilities to conduct surveillance at an unprecedented scale. Using a range of digital surveillance technologies and practices, and unprecedented public-private collaborations, intelligence agencies have extended their ability to collect, store and analyse data for intelligence purposes. Effective oversight is required to limit the potential for abuse. However, across Southern Africa – where digital surveillance is expanding – official oversight institutions typically lack the power and resources to monitor and review surveillance capabilities in order to ensure that intelligence agencies behave effectively and lawfully. Consequently, oversight in these countries typically is conducted by the public, through, for instance, challenging unjustifiable secrecy, publicising abuses and organising campaigns to rein these agencies in. Through comparative case study research exploring lessons from key moments in the region, this volume explores public oversight of intelligence-driven digital surveillance in eight Southern African countries and examines cases where this oversight either succeeded, failed, or achieved mixed outcomes. Authored by researchers and journalists from the fields of law, communication and media studies, this book offers lessons for academics and activists, suggesting that a new model of public oversight of surveillance is possible, and, arguably, functions better than extant approaches to surveillance. It will be of global significance, as surveillance abuses are a worldwide problem, as is the problem of oversight failing to keep pace with expanding surveillance capabilities.