Since the advent of Web 2.0, the interaction of user-generated content on participatory platforms has democratized content creation and reshaped communication, identity, authority, and knowledge across various fields, from health to politics, amid the post-truth phenomena. This timely book provides essential insights into the transformative effects of the evolving digital landscape. It gives a comprehensive analysis of how areas such as health, politics, and language ideology have been influenced by digital communication, and explores how online spaces have amplified minority voices, promoting inclusion and representation, while also addressing the backlash that challenges human rights associated with Internet use and the free exchange of information. The book also examines the intersection of law and digital crime, revealing the legal challenges posed by the online world. As our understanding of identity, knowledge, and authority increasingly intersects with Generative AI, it also discusses the impact of intelligent tools and the challenges they present.