Elon Musk took the stand as the first witness in his billion-dollar lawsuit against OpenAI in federal court in Oakland, California on April 28, 2026 [1]. The lawsuit, filed in 2024, claims that OpenAI CEO Sam Altman, co-founder and president Greg Brockman, and Microsoft betrayed OpenAI's original nonprofit mission meant to benefit humanity [1]. Musk said, "It's not OK to steal a charity," calling for changes to OpenAI's corporate structure, the removal of Altman and Brockman, and damages worth hundreds of billions that he says should go back to OpenAI's nonprofit arm [1].
Musk helped co-found OpenAI in 2015 but left its board in 2018 [1]. He told the court he only responded to the lawsuit after OpenAI publicly posted about the case, saying, "Only after they posted very publicly about this case, only then did I respond" [1]. OpenAI has denied the allegations and accused Musk of acting out of jealousy and regret over his departure from the company [1].
U.S. District Judge Yvonne Gonzalez Rogers cautioned both parties to keep the dispute off social media, warning, "Control your propensity to use social media to make things worse outside this courtroom" [1].
In a related development, Florida Attorney General James Uthmeier launched a criminal investigation into OpenAI and ChatGPT last week following chats reviewed by prosecutors after the 2025 Florida State University shooting [1].
The lawsuit contains demands for structural changes at OpenAI and seeks to redirect damages potentially amounting to hundreds of billions back to its nonprofit division. The trial continues as both sides present evidence and arguments concerning the future governance and mission of the AI research organization.