Yoel Roth’s family and friends have had to delete their Twitter accounts after Musk adopted QAnon-style tactics

Musk’s followers also directed harassment at professors who reviewed the dissertation that Roth wrote in 2016, as well as at his graduate school, the University of Pennsylvania, the person said. The university did not respond to a request for comment.

As head of trust and safety at Twitter, Roth was involved in many of the platform’s decisions about what posts to remove and what accounts to suspend. His communications with other Twitter officials have been posted in recent days as part of what Musk calls the Twitter Files, a series of tweets by conservative journalists Matt Taibbi and Bari Weiss.

Musk’s tweets to his tens of millions of followers have for years prompted his supporters to deluge the targets of his ire with online threats — famously, a participant in the rescue of a boys soccer team trapped in a cave in Thailand, whom Musk branded “pedo guy.” But now that Musk owns one of the most powerful social networks in the world and has gutted the company division that previously policed online harassment, the stakes are even higher.

Musk tweets about Roth recalled the QAnon conspiracy movement, which claims incorrectly that Democratic Party leaders direct a child sex abuse network.

“Looks like Yoel is arguing in favor of children being able to access adult Internet services in his PhD thesis,” Musk tweeted Saturday, attaching a screenshot of Roth’s dissertation.

Elon Musk boosts criticism of Twitter executives, prompting online attacks

In the text, Roth suggested that services like the gay dating app Grindr should adopt safety strategies to accommodate teenagers using their platforms, rather than drive them out entirely. Musk also commented on a 2010 tweet in which Roth wrote, “Can high school students ever meaningfully consent to sex with their teachers?” Roth then linked to an article about a Washington State Supreme Court ruling about what age students can consent to having sex with their teachers.

Musk’s critical comments about Roth are something of an about-face from his early days at the company, when Roth appeared to be one of the few high-level Twitter executives Musk supported. On Oct. 30, the billionaire tweeted, “I want to be clear that I support Yoel. My sense is that he has high integrity, and we are all entitled to our political beliefs.”

And Roth appeared measured in his comments on Twitter’s new owner, seeking to reassure the public about company efforts to fight hate and protect elections. He even appeared alongside Musk in a call intended to reassure advertisers.

Even after he left Twitter in November, Roth was muted in his criticism. He warned in an op-ed in the New York Times that there was “little need” for a trust and safety function at a company where “policies are defined by edict.” But he also said publicly that it wasn’t accurate to depict Musk as the “villain of the story” in his takeover of the company.

“I think one of the things that is tricky about Elon, in particular, is that people really want him to be the villain of the story, and they want him to be unequivocally wrong and bad, and everything he says is duplicitous,” Roth said during an interview at the Knight Foundation conference. “I have to say ... that wasn’t my experience with him.”

Musk’s ‘free speech’ agenda dismantles safety work at Twitter, insiders say

Still, Roth is the most visible former Twitter executive assessing Musk’s actions, and his role at the company has been highlighted in the Twitter Files.

Twitter employees have long been wary of Musk’s ability to stoke online criticism. Shortly after he announced his plans to take over the company in April, he tweeted a meme to his tens of millions of followers with the face of Twitter’s top lawyer, Vijaya Gadde, that appeared to suggest the company’s decisions are affected by a “left wing bias.”

Twitter users quickly piled on — calling on Musk to fire Gadde or using racist language to describe her. Gadde was born in India and immigrated to the United States as a child. One user said she would “go down in history as an appalling person.”

Such harassment is part of a years-long pattern for Musk, with few legal consequences to date. Musk ultimately was not held liable in a defamation suit brought after he made his “pedo guy” remarks.