Facebook follows its users activities by means of so-called social plug-ins, cookies, and pixels. These digital technologies enable Facebook to follow users’ behavior when online. Cookies, for example, are small files that are attached to your internet browser when you go online and visit a particular site. They are used to collect information about the kind of things you like to read or look at while surfing the web.
Facebook uses the data both for its own ends, but also to help advertisers send tailor made advertising. In so doing Facebook also uses certain cookies to follow people that don’t even have a Facebook profile.
The court ruled that it is “unclear what information Facebook is collecting about us” and “what it uses the information for”. Moreover, Facebook has not been given permission to keep tabs on internet-users by a court of law.