Hey man people always bring up this point, does anyone have MORE information about how that infrastructure works? I made a Facebook account for my class the oth

Hey man people always bring up this point, does anyone have MORE information about how that infrastructure works? I made a Facebook account for my class the other day, with nothing but my name and email. Now I'm 50 friends deep with old classmates // co-workers. Creepy. But HOW intrusive is this system?