“Localhost tracking” explained. It could cost Meta 32 billion.

Today's featured article comes from a different source than usual: ZERO PARTY DATA, a newsletter dedicated to gathering news from the world of data protection, edited by Jorge García Herrero and Darío López Rincón. The text we are presenting here is a simplified, yet accurate, explanation of “localhost tracking,” a controversial plan implemented by Meta.

Nowadays, it has become quite normal to come across a topic, person, or content on social media that you have previously searched for on the internet, whether it is an e-commerce site advertising its clothing or a video game about to be released. However, upon closer examination, it becomes clear that the connection between the two online environments should never have occurred, as the same account was not used.

Meta's ingenious plan mentioned above concerns precisely this kind of event, but it violates the privacy rules contained in various regulations, such as GDPR, DSA, and DMA. The process of localhost tracking is fascinating, yet terrifying, and you can find it described in detail in the newsletter presented here.