Concern is that Google could take advantage of the GDPR laws to use its global clout to restrict marketers' options for working with publishers and ad servers.

Google has already announced that it will no longer support some third-party ad serving on YouTube, or third party measurement companies on Google-owned sites in Europe.

Publishers worry that Google intends to create a situation where they're forced to work only with Google-approved vendors. Google has announced that it will require publishers to take "extra steps" in getting consent from users to use Google ad services, and that it plans to act as a "co-controller" of data along with the publisher. (Under GDPR, the controller determines how personal data of EU persons will be processed.)

Will the EU competition regulators be able to stay on top all that Google is doing in Europe?

Will the regulators go too far?

Stay tuned.