They (Swedish Radio) have done a few stories on Facebook pixel during the last year.

A year ago it was the state-owned pharmacy Apoteket that leaked customer information and their orders to Facebook. Once it was revealed that multiple pharmacies did it, an investigation into three of them was started. Last month SR extended their search and found 100 pharmacies in Europe doing the same thing. Leaking information to Facebook.

I'm sure this is a really common issue because it's so convenient and useful when doing the marketing and analysis. People don't think about the consequences or the fact that it's against the rules of Facebook.