X, formerly Twitter, has been at pains to lure back advertisers who deserted the platform in droves after Elon Musk’s takeover, slashing the site’s revenue in the process. Last month, the company even rolled out expanded features for brands, including tools to help keep their ads away from undesirable content like hate speech.

But those measures have proven wildly ineffective so far, at least where one major ad partner — the NFL — is concerned. Reports from Media Matters reveal that X has been serving the league’s promoted content on a number of verified and openly white nationalist accounts with a million followers between them. These include profiles for white supremacist Richard Spencer and VDare, an anti-immigrant organization (and Southern Poverty Law Center-designated hate group) that has specifically attacked the NFL and encouraged a boycott of the League over players supporting Black Lives Matter, denouncing the movement as “anti-white blood libel.”

NFL ads were also served on the account of Andrew Torba, CEO of the Nazi-infested rival website Gab, himself a notorious antisemite. When he retweeted a racist meme depicting a boat full of non-white migrants that warned “You’re being conquered,” an NFL clip from Sept. 14 game between the Minnesota Vikings and the Philadelphia Eagles appeared right below it.

X did not reply to a request for comment on the ad placements.

Media Matters noted that NFL spots — which are supposed to generate revenue for verified users whose timelines they appear on — likewise turned up in Rumble streaming host Stew Peters’ feed. Peters is a far-right conspiracy theorist who has regularly demonized Jews and LGBTQ people but is perhaps best known for his extreme anti-vax positions and spreading other falsehoods about Covid-19. He pushed the conspiracy theory that Buffalo Bills safety Damar Hamlin, who collapsed on the field in January due to cardiac arrest but went on to make a complete recovery, actually died because he was vaccinated and has been replaced by an actor.

It’s not the only time Peters has applied his dangerous anti-vax rhetoric to events in the league. On his show Wednesday, he interviewed “Christian activist” Morgan Ariel, who called for the deaths of Kansas City Chiefs tight end Travis Kelce and Taylor Swift, whom he’s rumored to be dating — because Kelce recently appeared in a Pfizer ad encouraging viewers to get their updated Covid-19 and flu shots.

“These people are responsible for murder,” Peters told Ariel, suggesting the celebrity couple’s popularity would lead children to be injected with a “weapon of biowarfare,” adding that “these people should be held to serious account.” Ariel went further, replying, “I think people deserve to be publicly prosecuted and hung.” (Peters has previously called for the hanging of Dr. Anthony Fauci and, like Ariel, makes constant reference to the execution of those who advocate for the Covid-19 vaccine, coining the catchphrase “Indict them, try them and fry them.”)

Sure enough, another NFL ad could be found just a few posts removed from the segment in which Peters’ guest endorsed the hanging of a star of the league. It’s not a total surprise, considering Peters’ reach on X — an audience of more than 400,000 followers — but it goes to show that the company has few if any working guardrails in place when it comes to ensuring that brands’ promotional materials don’t sit alongside violent extremism or hate speech. On Thursday, the video disappeared from Peters’ account, without no indication as to whether X removed it or Peters took it down himself.

The NFL’s chief media and business officer, Brian Rolapp, had kind words for X CEO Linda Yaccarino after participating in the company’s first “Client Council” last week, tweeting that under her leadership, the company “doing great work innovating to make the platform better for fans and partners.” And Yaccarino, for her part, has tried to spotlight the business relationship between X and the NFL as a success story for both.

But following Media Matters’ reports, the league sounded a note of alarm that could bode poorly for the partnership. “NFL unequivocally denounces any form of hate speech and has absolutely no association with these individuals or any group that promotes racism,” chief NFL spokesman Brian McCarthy told NBC Sports’ Pro Football Talk in a statement on Thursday. “As soon as this was brought to our attention, we immediately expressed our concerns to X to understand and rectify the issue.” McCarthy did not immediately respond to a followup request for comment.

It remains unclear whether X has taken the ads off the accounts in question, or what steps they may take to prevent the issue in the future. The NFL has not said whether it will continue to spend on the platform or pull its promotions there. Recently, Musk has taken to blaming the Anti-Defamation League for scaring off advertisers, amplifying the kind of antisemitic conspiracy theories Peters, Torba and others freely disseminate on his platform. But if he loses the most valuable sports league in the world, it could be thanks to his affinity for the very bigots who have him scapegoating everyone else.