I believe you should Google that kind of stuff instead of trying to make it a debate in comments. There is no single right move about what to do with the money, but governments are spending billions (including those from these fines) to build their countries https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Government_expenditure_on_general_public_services
We have known for more than a decade now that training machine learning models on huge user data sets allows to predict a lot of things with decent accuracy.
Twitter has been gathering a lot of data on all of its user, it is expected them to be able to predict interests like (and much more) this if you use their service.
No need to spy on your smartphone beside what you submit willingly https://hbr.org/2012/09/use-big-data-to-predict-your-c