Aside from the plethora of scummy privacy practices Facebook uses to track your every move on its myriad platforms, the company’s also come up with plenty of sneaky ways to keep tabs on you off its sites as well.

In exchange for giving these sites the power to track every pageview, purchase, search query, and much, much more, Facebook (naturally) requires that this data be shared with it, too.

In cases where the website visitor has an account on some Facebook platform, this offsite data just gets glombed onto whatever Facebook already knows about that person.

If they don’t have a Facebook account, then the company collects that data anyway, and uses it to create a “shadow profile” of that particular person.