As far as I know FB also does this. They create 'shadow profiles' around users who are not signed up to FB too. https://www.cnet.com/news/shadow-profiles-faceb

As far as I know FB also does this. They create 'shadow profiles' around users who are not signed up to FB too. https://www.cnet.com/news/shadow-profiles-facebook-has-information-you-didnt-hand-over/ https://www.cnet.com/news/shadow-profiles-facebook-has-infor...