The ethics and governance of health information is a major contemporary problem. The central dilemma is between the social utility gained by exploiting health data for public health purposes, and privacy concerns about collecting and using personal information. There is a discernible tendency in our digital age to prioritise privacy protection over social utility, which results in increasingly restrictive regulation of data, including health data. This book defends public health from this distinctive threat. The book starts with a comprehensive taxonomy of public health information - including a novel take on the notoriously vexed 'research-practice' distinction - and a discussion of the best governance arrangements for all public health information. Privacy is clearly central to this, so the concept of privacy is analysed to clarify the sort of privacy concerns relevant to public health information. This reveals that risks and harms associated with identifiable data are overstated - for example, when all public health data are assumed to be equally dangerous. Conversely, resources to manage privacy concerns about public health information are systematically understated. For one thing, public health should continue its traditional reliance on anonymization to protect individual privacy, despite increasingly sophisticated re-identification techniques. Also, the requirement to gain consent from individuals to use their information is offset by a duty to provide personal data for the sake of public health. In the same vein, the book ends with a discussion of trust, arguing that there are underemployed ways of increasing public trust in the institutions responsible for managing public health data.