When Elon Musk accused a rescue diver of being a “pedo” this weekend, the Tesla CEO adopted the far-right’s favorite allegation.

To a certain brand of conspiracy-minded conservative, pedophilia is everywhere. It’s in the basement of a Washington, D.C. pizza restaurant where, despite zero evidence, the fringe right claimed Democrats were running a child sex-trafficking ring. It’s in conservative internet personalities’ claims that their detractors are secretly attracted to children. Meanwhile, real sex abuse has haunted the Republican Party, where candidates and elected officials have recently been accused of sexually pursuing children or of covering up chronic abuse against a college wrestling team.

On Sunday, Musk took to Twitter and baselessly accused Vern Unsworth, a rescue diver who helped rescue a stranded Thai soccer team from a flooded cave, of being a pedophile.

Musk had previously waded into the crisis when he built a prototype submarine, which he claimed could rescue the children. During an interview after the children’s rescue, Unsworth criticized the sub as being too large to navigate the narrow cave. The sub “had absolutely no chance of working,” Unsworth said, calling the device a “PR stunt.”

Musk retaliated on Twitter. “We will make [a video] of the mini-sub/pod going all the way to Cave 5 no problemo,” he tweeted in response to Unsworth. “Sorry pedo guy, you really did ask for it.”

He also called Unsworth “sus” (short for “suspicious”) and doubled down on the pedophilia claims, offering a “signed dollar” that they were true, before deleting them. On Monday, Unsworth indicated that he was taking legal action against Musk.

Musk is the latest in a series of right-wing figures to smear their opponents as pedophiles.

“The whole concept of calling your enemies pedophiles or accusing them of being involved in a secret society isn’t new in conservative politics,” Jared Holt, a writer with Right Wing Watch told The Daily Beast. “It’s really a staple item of political discourse in America.”

Holt said the allegation has its roots in the “Satanic Panic” of the 1980s, when false allegations of ritual sex abuse evolved into a modern-day witch hunt. That panic, which included debunked conspiracies about Satanic sex abuse at childcare centers, was fueled in part by sensationalist media coverage and fundamentalist Christian outrage.

But the 2016 presidential elections kicked off a new Satanic Panic for the digital age. Just days before the election, a white supremacist posing as a Jewish lawyer on Twitter claimed Hillary Clinton was “at the center” of a pedophilia ring, BuzzFeed reported. The hoax took off on fringe-right forums before making its way to conspiracy news sites and eventually emerging as “Pizzagate,” a bizarre conspiracy that claimed children were being abused in a Satanic sex trafficking ring under Comet Pizza, a popular D.C. restaurant . Comet, other D.C. businesses, and other pizza companies outside the city reported death threats and vandalism.

The conspiracy ran wild until December 4, 2016, when a North Carolina man fired three shots into Comet Pizza with an AR-15. The man, who said he’d come to investigate child sex slavery, told police that he’d tried to convince other friends to watch Pizzagate conspiracy videos and join him on his raid at Comet Pizza.

While some of Pizzagate’s most vocal champions backed away out of embarrassment, many later coalesced around QAnon, an even broader and vaguer pedophilia conspiracy theory. The theory, which was recently promoted by a Florida GOP branch, stems from an anonymous 8chan user who claims to be a high-ranking government official. In series of cryptic and oft-debunked posts, the user “Q” claims President Donald Trump is not actually under investigation, but is just playing along to aid a real investigation into Satanic child sex abuse by virtually every enemy of the GOP: Democrats, Trump-critical Republicans, and Hollywood stars.

The theory and its allegations morph daily. In a podcast last week, conservative media personality and prominent QAnon promoter Liz Cronkin said Hillary Clinton was filmed eating a child’s face.

“There are videos that prove that Hillary Clinton is involved in child sex trafficking and pedophilia,” Cronkin said. “I have sources that have told me that; I trust these sources, so there is evidence that exists that proves that she is involved in this stuff … I believe with all my heart that this is true.”

Outside Tucson, Arizona a QAnon-flavored pedophilia conspiracy has leaked into the real world. After finding remnants of a homeless camp in a field, vigilantes claimed the site was actually a child sex-trafficking hotspot. Police refuted their claims and last week arrested the conspiracy’s leader (who has previously been arrested over various stunts and assault incidents) for trespassing.

And right-wing personalities have recently pioneered Musk’s tactic of calling detractors pedophiles. When video editor Vic Berger mocked Mike Cernovich, a conservative internet figure and former Pizzagate pusher, Cernovich repeatedly implied Berger was a child molestor and threatened to call Child Protective Services on him (Berger is a father). Cernovich has lobbied similar allegations at other opponents, accusing them of being pedophiles, date rapists, or pedophile supporters, New York Magazine reported.

Cernovich, who has previously claimed date rape does not exist, was accused of rape in 2003. The charge was dropped, although he performed community service for misdemeanor battery, according to the Southern Poverty Law Center.

When students and activists protested a speech by Cernovich at Columbia University in October, they also faced pedophilia allegations. The protesters were marching outside the school when at least two people unfurled a banner that read “No white supremacy, no pedo bashing, no Mike Cernovich,” over the logo for NAMBLA, a pro-pedophilia organization.

The people who brought the banner to the march quickly fled, and activists tore up the sign, protesters previously told The Daily Beast. But a picture of the banner, which appears to show anti-Cernovich activists supporting pedophilia, went viral with support from InfoWars personalities and Donald Trump Jr.

Right-wing trolls have also pushed a hoax claiming that the LGBT community wants to include pedophiles in its ranks. In 2016, the fact-checking site Snopes documented a 4chan campaign to photoshop fake “LGBTP” posters (the “P” stood for “pedosexual”). “Flood twitter with #lgbtp and #loveisageless with pics like this,” one user wrote over a newly made LGBTP graphic.

Iterations of the hoax remain in circulation, with a conservative news site authoring an article that passed the prank off as legitimate last week.

The pedophilia accusation has staying power because it’s one of the worst allegations possible, Holt said.

“If you accuse your enemies of some political misdoing, there can sometime be ways people will rationalize that away,” he said. “But I think there’s the reflex to call someone a pedophile because, in modern society, it is one of the most universally rejected offenses to commit. I don’t think anybody will come to the defense of a pedophile.”

Correction: This article previously referred to Mike Cernovich's battery charge as a sexual battery charge.