San Francisco, California - Silicon Valley investor Peter Thiel has branded Swedish climate activist Greta Thunberg and critics of artificial intelligence as "legionnaires of the Antichrist" during a series of private lectures.

The eight hours of lectures fused religious beliefs with warnings against technology regulation, according to recordings reviewed by The Washington Post.

In four roughly two-hour talks delivered over the past month at the Commonwealth Club in San Francisco, Thiel argued that those proposing limits on technology development threaten to bring about the destruction of the US and an era of global totalitarian rule, the Post reported Friday.

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Thiel, part of the so-called PayPal mafia that also includes Elon Musk, has a net worth that stands at around $27 billion and has close ties to the Trump administration, including Vice President JD Vance, a former associate.

He was also the only major figure from Silicon Valley who supported Donald Trump in his 2016 campaign to be president.

In Thiel's view, the biblical Antichrist is not an evil tech genius but someone who warns of existential risk nonstop and calls for strong regulation in innovative sectors.

"In the 21st century, the Antichrist is a Luddite who wants to stop all science. It's someone like Greta or Eliezer," Thiel said in his September 15 opening lecture, referring to Thunberg and AI critic Eliezer Yudkowsky, according to the recordings.

In his talk, the billionaire criticized financial regulations as signs that a world government has begun to emerge that could be taken over by an Antichrist figure.

"It's become quite difficult to hide one's money," Thiel said, describing an "incredible machinery of tax treaties, financial surveillance, and sanctions architecture" that gives wealthy people only an "illusion of power and autonomy."

The lectures come amid rising Christian nationalism in the US and as Silicon Valley leaders escalate their fight against AI regulation under President Trump's second term.