The global 'War on Terror' has brought a number of civil liberty and human rights issues into sharp focus. One in particular has caused a good deal of controversy, the use of arbitrary detention. The UN Working Group on Arbitrary Detention is the first guide to the jurisprudence and practices from the WGAD. Since its establishment in 1991, the Working Group has adopted more than 1,200 case opinions and conducted more than fifty country missions. In this book, these cases are presented in the style of a treatise, where the widest array of issues on arbitrary detention are placed in the context of the requirements of multilateral treaties and other relevant international standards. Written for both practitioners and scholars alike, this book will not only inform readers about the WGAD, but will also serve as an introduction to real case studies and provide legal practitioners with necessary procedural steps to file a claim.