On Facebook, there is not a single interaction that goes unnoticed by the platform.
But the company also tracks us outside its ecosystem, thanks to “Like” buttons on the pages of websites, as well as other embedded functionality controlled by Facebook such as ad placements, comments, or the ability to prove one’s identity using their Facebook account (“Log In With Facebook”).
The company encourages software developers to adopt such practices (most of them being invisible to the eyes of the public) in order to gather maximum intelligence about its audience, thus targeting users more accurately.
By being present on potentially any website or app, Facebook tracks our behaviour almost everywhere online with unprecedented precision—and even after we have logged out.