Ireland’s Data Protection Commission (DPC), which has supervisory authority over Google for the European Union, has launched its first major privacy investigation into the company since the EU’s General Data Protection Regulation (GDPR) came into effect last year.

The agency announced on Wednesday that it’s looking into Google’s personalised ad practices under Section 110 of Ireland’s Data Protection Act and GDPR, which restricted companies’ ability to legally collect, process and share consumers’ personal data without consent or a legitimate interest. Companies found to violate GDPR face a maximum fine of €20 million or 4% of annual turnover – more than $5 billion for Google.