Elon Musk informed a California jury on Wednesday that he messaged Sam Altman in early 2023 after learning that Microsoft had invested $10 billion in OpenAI, demanding to know "what on earth is going on?" Musk co-founded OpenAI with Altman over a decade ago. In his message, he characterized the move as a "bait-and-switch."

These remarks were made during Musk's second consecutive day of testimony in his civil lawsuit against OpenAI. He is attempting to convince the jury that the defendants, including Microsoft, have been "unjustly enriched by hundreds of billions of dollars." "Microsoft would only invest $10 billion—a massive amount—if it was confident of a return," Musk explained, detailing his frustration with the investment. OpenAI CEO Sam Altman was also present in the courtroom during Musk's testimony.

Under direct questioning from his lead attorney, Steven Molot, Musk expressed concern that Microsoft could effectively gain control over Artificial General Intelligence (AGI), which "started with a charity." "Microsoft's motivations are fundamentally different from those of a charity," Musk added. This represents Microsoft's second investment in OpenAI, following an initial $1 billion investment in 2019.

When asked why he did not file a lawsuit in 2019, Musk stated he understood at the time that profit participation was capped. Musk, who left OpenAI in 2018, said he believed Microsoft had "agreed to participate in a profit-capped manner." The lawsuit, which later named Microsoft as a defendant, alleges that Altman and Brockman deviated from OpenAI's founding principle as a non-profit organization dedicated to developing AI for the public good, not private interests.

In the suit, Musk claims he contributed $38 million in seed funding over the years to support this mission, only to be "betrayed" by OpenAI's transformation into a "profit-driven, market-dominating behemoth," effectively a "subsidiary of Microsoft." Microsoft's attorney, Russell Cohen, told the jury during Tuesday's opening statements that Microsoft "helped OpenAI pursue and advance its mission." "Unlike Mr. Musk, Microsoft never sought to control OpenAI," Cohen said.

In court on Wednesday, when asked about his response to these statements, Musk said, "They want to mislead the jury." Over the course of the month-long trial, the jury is expected to hear testimony from other major figures in the tech industry, including Altman, Brockman, and Microsoft CEO Satya Nadella.

OpenAI has repeatedly criticized Musk's lawsuit as "baseless." During opening statements, William Savitt, lead attorney for OpenAI and Altman, told the jury that Musk sued the developer of ChatGPT simply because he "didn't get his way at OpenAI." "The only thing Musk cares about is being in charge," Savitt said. While being cross-examined by Savitt on Wednesday, Musk accused the lawyer of trying to "trick" him. "Your questions are not simple. By their nature, they are designed to deceive me. Any simple answer would mislead the jury," Musk told Savitt.