We've all heard about the data breaches that happened with Facebook, the sharing and selling of information gathered by the platform.
So, just how pervasive is the spying function of Facebook??
I can only speak to my experience...
Long before I ever accepted the terms of service and joined Facebook, I was receiving emails about all my friends who had joined and offering the invitation to sign up.
Then, things got creepy : Facebook began sending me messages about my friends from different cities. They did not know each other, had never met, but they both knew me, and Facebook began sending messages that groups of my friends with no connection wanted me to join.
This means that Facebook had already taken an interest in trying to figure out who I am before I had ever even visited the site.