We are now in an age of almost overwhelming volumes of data about many people’s attitudes, circumstances and behaviour. Such data extends from people’s views to images of them, their locations and movements, and their communications. The data is very diverse; it includes lifelong health and prescrip­tion records, genetic biomarker profiles and family histories, satellite images, digital passports and their use, databases from product warranty forms, consumption trans­actions, online browsing records, email and web communications, social media, and mobile phone use. As Berners-Lee and Shadbolt (2011:1) highlight, ‘data is the new raw material of the 21st Century’.