Billionaire Elon Musk took the stand Tuesday to accuse OpenAI and its boss Sam Altman of betraying the AI company's altruistic origins, in a trial that could have far-reaching consequences for the industry and oblige the ChatGPT maker to profoundly revamp its business. At the heart of the case is Musk's accusation that Altman drove OpenAI to become a profit-seeking juggernaut looking to dethrone the likes of Google, Apple and Microsoft, and betraying its nonprofit mission.