The domains of personal data

By Johannes Ernst


Where does personal data exist? What does is describe?

If we use our broad definition:

My personal data is all data related to me or data that I have interacted with …

then the following diagram may be helpful:

Domains diagram

The columns in this diagram attempt to put personal data into some categories, like videos, social media, e-mail and the like.

And then the diagram lists some of the major companies that collect or store personal data in those categories. (This is done largely from an American perspective; other countries often have different market leaders.)

For example, we can see that many companies have some data about our interests, such as:

  • Facebook: from likes, shares, and the groups that we are members of (and potentially text analysis of what we posted)
  • Google: from search terms, likes and comments on YouTube etc
  • Amazon: from the purchases we made, and the products we searched for or browsed
  • Twitter
  • Reddit
  • LinkedIn

and probably many more.

Of course, this diagram – with as many boxes as it has – covers only a small and very incomplete list of companies that have our personal data. There are also many more categories of personal data than the columns shown in the diagram, including, for example, health-related data or financial data.

But the diagram, as incomplete as it is, gives us an idea about the size and scope of the problem.

Addition: Iain Henderson points out a similar diagram: