When examining the alleged role played by Cambridge Analytica, Facebook and "big data" in the Brexit referendum and the election of Donald Trump, it's worth looking at a book which opens by declaring that "is an attempt to explore a strange and rather exotic area of modern life." It continues:
It is about the way many of us are being influenced and manipulated – far more than we realise – in the patterns of our everyday lives. Large-scale efforts are being made, often with impressive success, to channel our unthinking habits, our purchasing decisions, and our thought processes by the use of insights gleaned from psychiatry and the social sciences. Typically these efforts take place beneath our level of awareness, so that the appeals which move us are often, in a sense, 'hidden'."