The Guardian view on data protection: a vital check on power

data is knowledge and knowledge is power. That is why data protection matters in a democracy. The most recent government paper, a statement of intent, is not the detailed legislation that will be needed to harmonise British law with the EU’s General Data Protection Regulation [GDPR], which comes into force next spring, but it gives a clear view of what the government is trying to achieve. The overwhelming aim is to remain in step with the EU. So much of a modern economy depends on the frictionless movement of vast quantities of data across national borders that it is vital to harmonise with EU policy even if we can now no longer help to shape it.

There are three different interests in data and privacy which have to be brought into balance: the individual, the companies which hold and process our data, and the state, which mediates between the two. There is a fundamental asymmetry between the individual and the other two, in that the personal data of any particular customer is worth in isolation very little to anyone else, but the aggregation and refinement of data gives it a huge new value. It should be the aim of policy to ensure that no one is disadvantaged by having their data processed in this way.

Anonymity is not the shield it might appear. Someone who knows everything about you but your name is in possession of information far more valuable, and potentially dangerous, than someone who knows your name and nothing else. Names can be trivial to discover, given other facts. One of the central premises of the information economy is that the collection and analysis of gigantic quantities of anonymised data produces general patterns which enable accurate prediction about anonymised individuals. The correlations that emerge from vast quantities of data hold good even when tiny samples are examined.