Justice Department claims the EU overreached by pursuing X's owner and wider corporate empire.
The US government wants to join Elon Musk and X's legal challenge to the European Commission's €120 million fine against the social media platform.
The Commission issued its first fine under the Digital Services Act in December 2025, finding that X had breached transparency rules through its paid blue checkmarks, advertising repository, and restrictions on researchers' access to public data.
X owner Elon Musk described the decision as "crazy" and "insane" in a Xeet, and compared the "woke" Commission to "Stasi commissars," combining two different references.
Before issuing a response, he shared the comments made by FCC chair Brendan Carr, who accused "Europe" of "fining a successful US tech company for being a successful US tech company."
US politicians also rallied around Musk. Senator Ted Cruz called the fine "an abomination" and an attack on American free speech.
The US government has now applied to intervene in the cases brought by Musk and X Internet and X Holdings, supporting their attempts to annul the Commission's decision.
Assistant Attorney General Brett A. Shumate accused the Commission of regulatory overreach against US companies beyond its jurisdiction.
The Justice Department said it has "significant concerns" about how the Commission determined which people and companies constituted the provider of X's digital service.
According to the DoJ, the Commission found the parties jointly and severally liable for the €120 million fine and calculated it using the worldwide turnover of the corporate group controlled by Musk.