X (formerly Twitter) has filed an appeal against the €120 million penalty imposed by the European Commission under the Digital Services Act (DSA), marking the first judicial challenge to enforcement of the landmark European law. The case, now before the General Court of the European Union, is shaping up to be a crucial test for how the Digital Services Act (DSA) will be interpreted, and enforced—against large online platforms.

The penalty, announced in December 2025, focuses on what regulators described as serious transparency failures, including the platform’s handling of its paid verification system, advertising disclosures, and access to public data for researchers.

Confirming the a...