Austrian privacy advocate Max Schrems has levied a complaint against Google, accusing the search giant of tracking users and passing the info to advertisers.

Google has been mired in privacy and antitrust issues in the EU, generally considered to be the most privacy and consumer-focused part of the world. EU regulators have repeatedly hit Google with billions of dollars in fines, in 2017, ’18 and ’19.

Now Bloomberg is reporting that Schrems campaign group Noyb has accused Google of using a unique ID to track Android users without the proper opt-in consent.

“Google does not collect valid ‘opt-in’ consent before generating the tracking ID, but seems to generate these IDs without user consent,” according to the group.

“Android does not allow deleting the tracking ID. It only allows users to generate a new tracking ID to replace the existing tracking ID. This neither deletes the data that was collected before, nor stops tracking going forward.”

If the claim has merit, the EU’s GDPR laws allow for fines up to “4% of a company’s global annual sales.” If Google is found guilty, the result could be one of its biggest fines yet.