I once talked with a colleague from the data-analysis field. Apparently the company they work at is somewhat in the legally grey area.
They advised other companies on hiring candidates, by scraping all possible data about them online (which included buying anonymized advertising data and correlating it to all their publically available data and the data from the application). Using that, they claim to predict worker motivation, loyalty, how often they are sick, their political alignment, what their acceptable rate is, if they are going to ask for a raise, how well they work under pressure and much much more.
Since hearing it this has basically become my thread model.
As I am writing this, I realize that it is probably time to delete my Lemmy account and never post here again lol