Elon Musk faced a growing backlash on Friday from lawmakers on both sides of the Atlantic, with threats of fines and sanctions, after Twitter suspended the accounts of at least eight journalists on Thursday without warning.
The suspended accounts included those belonging to Ryan Mac of The New York Times, Donie O’Sullivan of CNN and Drew Harwell of The Washington Post. It was unclear what the suspensions had in common.
The silencing of prominent voices could raise the regulatory heat on Twitter, and possibly Mr. Musk’s other companies, including Tesla and SpaceX, which is a big recipient of government funding and projects. It could also hurt his push to get reluctant advertisers back onto the platform.
The action set off a wave of protests. News organizations, including The Times and CNN, have demanded that Mr. Musk explain his rationale. Supporters of the journalists argued on Twitter that the move was overly punitive.
Lawmakers in the European Union may go on the offensive. Vera Jourova, a vice president of the European Commission, said the move violated the E.U.’s Digital Services Act and its Media Freedom Act.
“There are red lines. And sanctions, soon,” she tweeted Friday morning.
The recently ratified Digital Services Act serves as a kind of rule book on moderating content for firms operating in the bloc. It goes into effect next year, and carries a fine of 6 percent of global revenue for companies that run afoul of the rules.
Representative Lori Trahan, Democrat of Massachusetts and a member of the House committee on electronic communications and the internet, also expressed dismay over Twitter’s move. She tweeted on Thursday that she had received assurances this week from the company that it had no intention of retaliating against journalists or independent researchers who cover Mr. Musk and Twitter critically.
“Less than 12 hours later, multiple technology reporters have been suspended. What’s the deal, @elonmusk?” she wrote.
The moves came a day after Twitter suspended more than two dozen other accounts, including an account belonging to Jack Sweeney, the 20-year-old college student behind @elonjet, which tracked the movements of Mr. Musk’s private plane. Each of the suspended journalists had written about the plane-tracking account or tweeted about it.
The billionaire tech mogul, who has described himself as a free speech absolutist, introduced a new red line this week after he claimed that a car carrying one of his children was accosted by a “crazy stalker.” The rule: Any Twitter user who publishes the live location or other personal information of someone else — an act known as doxxing — will be taken offline.
In a Twitter Spaces discussion, Mr. Musk defended the decision to block the journalists. “You doxx, you get suspended, end of story,” he said, and then abruptly left the call.
It’s unclear how long the suspensions will last. On Friday, Mr. Musk polled his 121 million followers, asking them to vote on when accounts that shared his location should be reinstated. As of 8:30 a.m. Eastern time, nearly 60 percent had voted “now.” (The poll will run for another 14 hours.)