The letter is two pages, dated Friday, and on Department of Justice letterhead. It was sent by the DOJ's Office of International Affairs to the Paris prosecutor's office. It refuses to cooperate with the French criminal investigation into X Corp., the social media platform owned by Elon Musk. [1] The Wall Street Journal obtained the document and reported its contents on Saturday. The core sentence: the French investigation "seeks to use the criminal legal system in France to regulate a public square for the free expression of ideas and opinions in a manner contrary to the First Amendment of the United States Constitution." [2]

The French probe began in January 2025, when a lawmaker and another French official lodged complaints that X's content-selection algorithm amounted to foreign interference. Paris prosecutors opened a preliminary inquiry in July, brought police into the investigation, and in February 2026 raided X's French offices. They subsequently issued summonses to Musk and Linda Yaccarino, the former CEO of X, to appear for interviews on Monday, April 20 — tomorrow. [3] The French case, meanwhile, has expanded to cover alleged antisemitic content, Holocaust denial posts, disseminated child sexual abuse material, and nonconsensual sexual deepfakes generated through X's AI tool, Grok. [4]

The paper's April 18 piece on press-freedom mechanisms named four parallel reductions of press and platform accountability visible in a single week. The DOJ letter on X is a fifth mechanism, and it is qualitatively different from the others. CBS Radio went silent because Paramount-Skydance decided it would. The Pentagon corridor closed because the administration ruled. Novaya Gazeta paused because a Russian court held. The Disney-ABC News cuts happened because a corporate parent chose. The X refusal is the only one of the five where the United States federal government has used a constitutional instrument — the First Amendment — as a tool of foreign policy against an ally's active criminal process.

What the letter says

The Office of International Affairs is the DOJ unit that handles mutual legal assistance treaty requests. The U.S.-France MLAT has been the framework for cross-border criminal cooperation between the two countries since 1998. French prosecutors had submitted three separate requests for U.S. assistance this year, according to The Hill's summary of the letter. [5] The Friday document declines all three. The DOJ characterizes the French effort as "an effort to entangle the United States in a politically charged criminal proceeding aimed at wrongfully regulating through prosecution the business activities of a social media platform." [6]

An xAI official told the Journal: "We are grateful to the Justice Department for rejecting this effort by a prosecutor in Paris to compel our CEO and several employees to sit for interviews." The company added that it hopes French prosecutors "recognize that there is no wrongdoing here, and terminate their baseless investigation." [7] Musk's own X post was shorter: "Indeed, this needs to stop." The French MFA did not respond over the weekend. The European Commission, which has a separate €120 million Digital Services Act case against X pending from December, did not publicly comment.

What the refusal does

The First Amendment applies to the United States government's own capacity to regulate speech. It does not, as a matter of constitutional doctrine, bind French prosecutors or French law. What the DOJ letter does, formally, is decline to share evidence — data held by U.S.-incorporated X entities, testimony from U.S.-resident executives — with a French criminal process that is examining alleged conduct within French jurisdiction. The refusal does not stop French prosecutors from proceeding. It stops them from proceeding with American cooperation.

The operational question is whether Monday's summons of Musk and Yaccarino is pursued in the absence of compliance. French prosecutors have, in past tech cases — the Pavel Durov case against Telegram being the most recent — issued international arrest warrants when targets did not comply with summonses. [8] If the French prosecutor's office follows precedent, an international warrant against Musk is plausible within weeks of nonappearance. Whether such a warrant would be executed in a Paris transit incident is a separate question. Whether the Trump administration would then issue a formal political response — diplomatic expulsions, travel advisories, trade measures — is a further question the Friday letter has teed up without yet resolving.

The Europe-wide exposure is not hypothetical. X is currently under investigation by the European Union under the Digital Services Act for inadequate risk assessment on Grok's AI outputs; it is fighting a €140 million fine on appeal. The UK's Information Commissioner's Office opened a formal investigation in February. German authorities are monitoring X's German operations under separate content laws. If the DOJ letter establishes a precedent — American citizens and American-domiciled platforms are not available for European criminal cooperation where the underlying conduct is speech-coded — then the letter is not really about France. It is the opening move of a larger reorientation of U.S. assistance treaty posture under the Trump administration, with X as the test case.

What France will do Monday

The Paris Prosecutor's office, through its press line on Saturday, told the Indian wire service Inshorts that it had "no knowledge" of any DOJ letter. [9] The public posture is that the investigation proceeds. The summons for Musk and Yaccarino remains scheduled for Monday. In the event of nonappearance — Musk's attendance has been called "doubtful" in French reporting since the raid — French procedural law allows the prosecutor to proceed to the next stage of inquiry without the in-person testimony. Whether that stage involves a judicial warrant depends on the prosecutor's assessment of the evidence already collected from the February raid and from independent researchers and institutions the office has engaged.

French digital-rights NGOs, notably La Quadrature du Net, framed the DOJ letter over the weekend as "an unprecedented assertion of First Amendment extraterritoriality." The phrase is not a term of art, but it is the correct description of what the letter does. American law does not travel through MLAT cooperation. American refusal to cooperate, based on American law, does. The distinction is the entire content of the Friday letter.

Elon Musk is now protected from French investigative process by a unit of the United States Department of Justice that, six months ago, did not appear on the menu of instruments available to an American billionaire facing European criminal inquiry. The instrument has appeared. On Monday morning, Paris will test whether the instrument's appearance changes the scheduled hearing. The paper will report what Monday does with the test. On Sunday, the instrument itself — a two-page letter dated Friday — is the news.

-- MAYA CALLOWAY, New York