Privacy by design is a proactive approach that promotes privacy and data protection compliance throughout project lifecycles when storing or accessing personal data. Privacy by design is essential for the Internet of Things (IoT) as privacy concerns and accountability are being raised in an increasingly connected world. What becomes of data generated, collected or processed by the IoT is clearly an important question for all involved in the development, manufacturing, applications and use of related technologies. But this IoT concept does not work well with the 'big data' trend of aggregating pools of data for new applications. Developers need to address privacy and security issues and legislative requirements at the design stage, and not as an afterthought. In this edited book, the authors draw on a wealth of interdisciplinary research to delineate the challenges of building accountability into the Internet of Things and solutions for delivering on this critical societal challenge. This advanced book brings together legal-tech scholars, computer scientists, human computer interaction researchers and designers, and social scientists to address these challenges and elaborate solutions. It articulates the accountability principle in law and how it impacts IoT development, presents empirical studies of accountability in action and its implications for IoT development, brings technological responses to the requirements of GDPR and ways of building accountability into the IoT, and covers compliant IoT application development, privacy-preserving data analytics, human-centred IoT security, human-data interaction, and the methodological challenge of understanding and responding to the adoption of future technologies in everyday life.