Question about Facebook's "shadow profiles"

Web: https://www.reddit.com/r/privacy/comments/rz7nns/question_about_facebooks_shadow_profiles/

Hello there, I am a first semester student majoring in CeyberSec and I learned that Facebook use social Plugins to gather data about their users, and if someone is not a user of Facebook they will create what's called "shadow Profiles".

Well, it kind of sounds unreal to me (I know it is real), but lets say every time I use my browser to go to a website that has social plugins Facebook will have to create a this cookie …

facebook privacy shadow