This thesis is an anthropological study of Internet sexual offending, more specifically the viewing of child abuse media. It is based on 17 months of participant-observation in UK group programs for individuals who had downloaded illegal child abuse media, semi-structured interviews with participants, program staff, and police, and staff focus groups. Through engaging directly with offenders and those managing them, it provides an in-depth, qualitative understanding of how Internet use and perceptions of online spaces play a key role in Internet sexual offending, while also asking broader questions about online sociality, morality, and effects on normative behaviour. The central argument posits that in moving beyond commonplace explanations for Internet offending, more attention must be given to Internet use, perceptions and constructions of online spaces, and effects on social norms to explain this phenomenon. It then follows to suggest that for some offenders, these elements can be instrumental in their sexualization of children and choice to view abusive media. The thesis specifically explores why and how some people in the UK engage with illegal child abuse media, with particular attention to notions of risk, childhood, morality, and the Internet. Employing Foucauldian and neo-Foucauldian theory, anthropology of the Internet, and constructionist theories of childhood, focus is placed on multiple areas: the potential social, emotional, sexual, and Internet-specific factors associated with offending; participants' relationships with the Internet and constructions of online spaces; participants' perceptions of childhood and children online and offline; and, societal and institutional efforts to respond to the above, including the larger justice system and fieldwork group program. The general research areas are social science of the Internet, childhood studies, human sexuality, group therapeutic processes, policy and law, and research methodology and ethics.