European Parliament recently called on a ban on micro-targeted ads. Such a decision made by a democratically elected body is somewhat unprecedented.

Micro-targeting allows people (i.e. “advertisers”) to use platform profiling to reach the “right” audience. For example targeting content based on traits such as: Male/Female, age, the location (i.e. based in Brussels), or preferences (i.e.  "likes yoghurt"), so on so on.


It so happens that I am among the firsts who researched the technology underlying micro-targeting - the Real-Time Bidding (RTB).

  • In 2014 the research work Selling Off Privacy at Auction explored what happens to user data in the RTB medium, during the auction involving user data and the monetary payment “bidders” intend to pay for displaying a targeted ad. We demonstrated several data leaks.
  • This analysis was further reinforced in a further scientific report To bid or not to bid? Measuring the value of privacy in RTB, where we analyzed the mechanics of targeting and identified further data leaks. Our works were among the very first speaking on the topic of privacy in microtargeting.
  • In 2016 I also explained (quite before this matter became somewhat a top concern due to the later disclosed big abuses…), how this micro-targeting channel can be abused to influence the entire nation’s democratic elections.

Since then many developments happened. CambridgeAnalytica abuses became loud. Platforms such as Facebook or TikTok limited the scope of micro-targeting to a minimum of 1000 users (and such precautions were also demonstrated to be bypassed, etc), among many other developments. Real-Time Bidding remains among the primary technologies in political targeting. The transparency aspects I called for are still lacking.

And in 2020 Members of the European Parliament voted to call forthe European Commission to ban platforms from displaying micro-targeted advertisements and to increase transparency for users”.

The story did not yet reach its end. For example, we still lack the tangible and real transparency technology layer (some ideas exist, but they have no platform support). For example, platforms never disclose who exactly (and how many of them) got to inspect the user data during the RTB auction. So user's don't know this. Privacy or transparency technology can be designed, but there needs to be willingness, or incentives, or both.

Things move, but slowly. Perhaps this is how it needs to be? Perhaps. Perhaps not?