“Our personal data reflects our interests, our desires: it is a digital extension of our soul. By giving it away so freely to social networks, supermarket loyalty cards and internet search engines have we engaged in some form of Faustian pact? Our digital souls may not be immortal, but they can certainly outlive us. What we choose to share also affects those around us: my wife and I may be happy to share information about our genetics, but by doing so we are also sharing information about our children’s genomes. Using a supermarket loyalty card gains us discounts on our weekly shop, but also gives the supermarket detailed information about our family diet.”

https://www.theguardian.com/media-network/2015/mar/05/digital-oligarchy-algorithms-personal-data?