This book explores the potentials - and perils and pitfalls - of the new technology of pervasive adaptation. Miniaturisation and Moore's Law have combined to make pervasive computing a reality, while advances in intelligent software make adaptation of those pervasive computing environments possible. This opens up a wide range of interesting and beneficial applications in health, commerce and entertainment; it also offers the possibility of every behaviour, preference and even emotion being sensed and recorded digitally, and then, possibly, being used in a way that is less desirable: for surveillance, invasions of privacy, reduction or removal of rights. This Pervasive Day: The Potential and Perils of Pervasive Computing will investigate the science and technology of pervasive adaptation from a human-centred perspective, and consider social, ethical and legal issues. It will offer an overall view of innovative technologies from a techno-political standpoint, with recommendations where research should (or not) go into, as well as bringing up specific controversial issues, on which some of the contributors might not be in full agreement.