Elon Musk’s social media company X breached EU online content rules, EU tech regulators ruled on Friday in a finding that could lead to a fine and significant changes in how it operates.

The charges by the European Commission, the first issued under the Digital Services Act (DSA), follow a seven-month long investigation. The new rules require very large online platforms and search engines to do more to tackle illegal content and risks to public security.

The EU executive’s preliminary findings or charges sent to X targeted the company’s dark patterns, advertising transparency and data access for researchers.

It said X’s verified accounts which carry a blue checkmark do not correspond to industry practice and negatively affect users’ ability to make free and informed decisions about the authenticity of the accounts they interact with.