Ireland’s Data Protection Commission has launched its first major privacy investigation into Google since the European Union’s General Data Protection Regulation went into effect last year.

The agency announced Wednesday that it’s looking into Google’s personalized 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 euros or 4% of annual turnover, more than $5 billion for Google.