This motley set of characteristics, attitudes, thoughts, and desires come very close to defining me as a person. It is also a precise and accurate description of what a group of companies I had never heard of, personal data trackers, had learned about me. My journey to uncover what data companies knew began in 2014, when I became curious about the murky world of data brokers, a multi-billion-pound industry of companies that collect, package, and sell detailed profiles of individuals based on their online and offline behaviours.

What I found out shocked me, and reinforced my anxieties about a profit-led system designed to log behaviours every time we interact with the connected world. I already knew about my daily records being collected by services such as Google Maps, Search, Facebook, or contactless credit card transactions. But you combine that with public information such as land registry, council tax, or voter records, along with my shopping habits and real-time health and location information, and these benign data sets begin to reveal a lot, such as whether you’re optimistic, political, ambitious, or a risk-taker. Even as you’re listening to me, you may be sedentary, but your smartphone can reveal your exact location, and even your posture. Your life is being converted into such a data package to be sold on. Ultimately, you are the product.

https://www.ted.com/talks/madhumita_murgia_how_data_brokers_sell_your_identity