It sounds similar to what's called a shadow profile. Facebook does that[0], and it's usually considered a bit sketchy (and possibly illegal). [0]: https://www.

It sounds similar to what's called a shadow profile. Facebook does that[0], and it's usually considered a bit sketchy (and possibly illegal). [0]: https://www.theverge.com/2018/4/11/17225482/facebook-shadow-profiles-zuckerberg-congress-data-privacy https://www.theverge.com/2018/4/11/17225482/facebook-shadow-...