“Remember the Minitel” could be the rallying cry of graying French political irritant Thierry Breton. The Minitel, those of a certain age will remember, was the ill-fated French riposte to CompuServe. It was run by the state subsidized France Télécom. Mr. Breton once served as CEO of the defunct telecom and now serves as the EU’s internal market commissioner. One of the things he has a penchant for doing in that capacity, apparently, is writing needling letters to Elon Musk.

On Monday Mr. Breton sent a lengthy letter to Elon Musk telling the owner of the social media platform X — ahead of his interview later that day with former President Trump — that he needed to censor potentially “harmful content” on X.  

While Mr. Musk’s interview with the Republican nominee for president took place outside the European Union, Mr. Breton maintained that the content of the livestream could still have an impact public policy within the EU, and would therefore be subject to the EU’s new Digital Service Act. The CEO of X, Linda Yaccarino, described Breton’s letter as “an unprecedented attempt to extend a law intended for Europe to political activities in the U.S.”

In his own post on X, Mr. Breton appeared to channel some verbiage from the movie “Spiderman,” writing that “with great audience comes great responsibility.” The line from the film is “with great power comes great responsibility. Below that Mr. Breton added that “as there is a risk of amplification of potentially harmful content in the EU in connection with events with major audience [sic] around the world, I sent this letter to Elon Musk.”

In the letter, Monsieur Breton wrote, inter alia, that Monsieur Musk needed to inform the EU about “the measures taken to address their orders against content considered illegal according to national and/or EU law.” He also made an attempt to link X to “the recent riots in the UK.” He reminded the X owner that “formal proceedings are already ongoing against X under the DSA, notably in areas linked to the dissemination of illegal content and the effectiveness of the measures taken to combat disinformation.”

Those proceedings began last year when Mr. Breton started marinating his beef with Mr. Musk with a formal request for information.  Mr. Musk, for his part, responded to Mr. Breton by posting a meme from the 2008 film “Tropic Thunder,” which included a candid suggestion of what Mr. Breton could do with his face. 

The Trump campaign did not exactly warm to the 69-year-old Frenchman’s prickly epistle either. Campaign worker Chris LaCivita wrote that “European Union is attempting to meddle in the US election…they can go to hell.” Mr. Trump’s former ambassador to Berlin, Richard Grenell, called Mr. Breton and the EU “enemies of free speech.”

It is an accepted fact of life that the French are persnickety, but this time Mr. Breton may not only have gone too far but exceeded his authority. On Tuesday the European Commission — which employs Mr. Breton — implied that he dispatched the letter without the approval of the commission’s president, Ursula von der Leyen. The commission stated that “the timing and the wording of the letter” were “neither coordinated or agreed” with the president nor with the commissioners.

Yet the European Commission indicated this week that its investigation of alleged dissemination on X of what it calls “illegal content and information manipulation” is ongoing. Whether Mr. Breton or any other Brussels paladin actually tuned in to the convivial exchange between messrs Musk and Trump this week was not immediately clear — and may never be known.