Last month, X users spotted an ad on the social media platform from the @AppleTV account for the second season of Severance.

The promo marked a conspicuous return for Apple to advertising on X in more than a year after pausing campaigns due to the rise of far-right content on the network that appeared alongside ads and backlash against Elon Musk grounded in criticism that he endorsed antisemitic conspiracy theories. It coincided with a period around the time of his political ascension that saw a flurry of other brands resume or increase spending on X, namely Amazon. Concerns that Musk is leveraging his influence in the Trump administration have been cited by five Democratic senators, who asked the Justice Department to investigate whether Musk is violating federal ethics laws.

Senators Elizabeth Warren, Cory Booker, Richard Blumenthal, Adam Schiff, and Chris Van Hollen on Wednesday wrote to the Justice Department over the possibility that Musk is strong-arming businesses into returning to X under the threat of retaliation. They cited an incident in which an attorney for the company allegedly demanded that advertising conglomerate Interpublic Group get its clients to spend more on Elon Musks social media platform, or else, reported by The Wall Street Journal.

Interpublic understood the implication of this threat: if its advertisers do not generate more revenue for X, it would face the risk that Musk could use his power in the Trump Administration to delay, or even block, Interpublics pending $13 billion dollar merger with its rival a merger that requires review by antitrust enforcers such as the DOJ, the letter stated.

Musk is currently the head of theDepartment of Government Efficiency and is regularly seen alongside Trump at the White House. Shortly after he bought then-Twitter in 2022, he immediately moved to steer the platform toward his free speech ideals. This included reinstating banned accounts, such as those from Kanye West and Donald Trump, and launching a new paid verification system that allowed some users to impersonate brands.

The loosening of content-moderation restrictions sparked an exodus of advertisers over concerns that their ads appear next to or are associated with controversial content. A report from nonprofit Media Matters for America, which has been sued by Musk, released last year alleged that the platform was placing ads for companies such as Apple, Bravo (NBCUniversal), IBM, Oracle and Xfinity (Comcast) next to content that touts Adolf Hitler and his Nazi Party. Disney, Warner Bros. Discovery, Paramount, Sony Pictures and Lionsgate were among the major advertisers that backed away from the platform.

In the letter, the senators said that Musk started to threaten policy repercussions against advertisers as he began for his new role in the administration. They urged federal prosecutors to probe him for potential violations of ethics laws, including a prohibition on bribery and another that bars him from participating in matters in which he has a financial interest.

In this case, DOJs decision on whether to thwart the Interpublic merger is now potentially linked to Xs advertising revenue which would give Musk a direct stake in the outcome, the senators wrote.

In a separate letter, the senators also wrote to the Federal Trade Commission over the possibility that Musk may retaliate against Interpublic by pressuring the agency to block its merger or bribe the conglomerate by directing Trump to allow its deal with Omnicom to proceed in exchange for getting its clients to spend more on X. They pointed to a significant conflict of interest between Musks government position and his various businesses. (Interpublic has recently signed a new deal with X for potential ad spending, according to The Wall Street Journal.)

Disney, Lionsgate, Warner Bros. Discovery and Comcast, among others, have resumed advertising on X, according to market intelligence firm MediaRadar. Still, companies collectively spent less than $3.3 million from January to September, which represents a 98 percent decline from the same period last year.

The resumption of spending by Disney, which resumed ad campaigns over the summer, and Apple were particularly encouraging signs for X because they were among its largest advertisers before Musk took over.

Last year, the Justice Department filed a landmark antitrust lawsuit against Apple targeting its alleged monopoly over the smartphone market and practices meant to keep consumers dependent on iPhones while preventing them from switching to rival devices.