US demands to be heard in the X fine case: the dispute concerns jurisdiction, not the size of the fine

US demands to be heard in the X fine case: the dispute concerns jurisdiction, not the size of the fine

On 24 September 2026, the US Department of Justice (DOJ) filed a request to intervene as a supporting party for X and Elon Musk in their annulment action against the EU's first fine under the Digital Services Act – €120 million. The Commission responded the next day that it is ready to defend the fine in court, and the General Court in Luxembourg has not yet decided whether the US will be allowed to intervene at all. That is where the decision point now lies.

A rare move by a foreign state

It is unusual for another state's justice department to enter as a supporting party in a case before the EU's courts. AP describes the intervention as "a rare move," and according to The Next Web, the State Department contributed to drafting the filing.

The legal mechanism is Article 40 of the court's statute. It gives a state the right to take part in a case if it can show an interest in the outcome. That is precisely the test the General Court must now assess: does the US have a sufficient interest in how the EU calculates fines against an American company – and against Musk personally – to have its say?

DOJ's answer is yes, and the justification is not primarily that the fine is too high or that its content is wrong. It is the jurisdiction question that carries the objection. According to The Next Web, the fine applies to X and Musk jointly, and the Commission based it on the worldwide turnover of businesses Musk controls. DOJ argues that this hits Musk personally and companies with no connection to X. In its statement, as reported by BBC via Yahoo News, DOJ said the US "has a clear interest" in the Commission's decisions being applied consistently with "how territorial jurisdiction is generally understood in international law."

What the fine was actually about

The €120 million fine was the first sanction under the Digital Services Act and followed a two-year investigation, Reuters writes. The Commission issued its decision on 5 December 2025.

The breakdown, as reported by Hoodline citing Euractiv, shows three distinct violations:

• €45 million for misleading practices around the blue checkmarks – the verification badge paid users could obtain, which no longer signalled identity verification.
• €40 million for denying independent researchers access to platform data, as the DSA requires.
• €35 million for failure to comply with the requirements for the ads repository.

No precise dollar figure can be given: sources cite conversions ranging from $136 to $140 million, suggesting approximate conversions. The euro amount is consistent across all sources.

The procedure: two pending cases in Luxembourg

X and Musk had no intention of letting the fine stand unchallenged. On 16 February 2026, the companies and Musk filed three separate actions at the General Court, according to Hoodline citing the court's documents. Two cases are pending:

• T-114/26 – X Internet and X Holdings v. Commission.
• T-121/26 – Musk in his own name v. Commission.

Both seek to have the Commission's decision of 5 December 2025 annulled. DOJ's request to intervene covers both cases, according to The Next Web.

The Commission responds: "We do not need to be informed of anything"

The Commission met the intervention with diplomatic tone and legal firmness. Spokesperson Thomas Regnier told reporters, according to AP:

"We enforce our legislation objectively, transparently and with a solid case. We are ready to defend our position in court. We have plenty of evidence at our disposal, and as always it will be up to the court to decide."

When Regnier was asked whether DOJ had informed the Commission that it intended to back Musk, he replied: "We do not need to be informed of anything."

Regnier also stressed, according to AP, that the case should not affect EU–US relations more generally.

The political backdrop

The legal battle does not stand in a vacuum. President Trump has characterised the fine as censorship, and the State Department has imposed sanctions on five individuals – among them former EU Commissioner Thierry Breton, according to The Next Web and IJR. This is important context for understanding why a justice department finds it natural to spend resources on a European fine against an American company, but it is not the legal core of the case: DOJ's objection before the court concerns the turnover basis and territorial jurisdiction.

The intervention also comes as the Commission, in January 2026, opened a separate, broader investigation into X related to the AI chatbot Grok, which had generated sexually explicit images, including of children, The New York Times writes. That case has so far not been backed by fines.

What will now decide the case

Two questions remain unresolved, and both will shape the outcome:

First: will the US be heard as a supporting party? The General Court has not decided whether the request meets Article 40's requirement of an interest in the outcome. If the court says yes, that is in itself remarkable – an American state voice in an EU court proceeding – and DOJ gets the chance to argue its territorial jurisdiction line directly. If the court says no, the dispute remains between X, Musk and the Commission.

Then: does the use of worldwide turnover hold up? The core of DOJ's objection is that the Commission calculated the fine on the turnover of the entire Musk group, not just X. That raises the question of whether an EU fine against a company can reach into a morass of affiliated undertakings – and to the owner personally – while remaining consistent with international law's understanding of territorial jurisdiction. The General Court must assess whether that calculation method was correct. The outcome could matter for how the Commission calculates DSA fines in the future, but how any court rulings would affect other American tech regulation in Europe is not something the court or the Commission has addressed – it would be speculation to commit to anything there.

What happens next will, in other words, first be decided by a procedural ruling in Luxembourg: whether the American state is let into the case or not.