Greg Brockman, OpenAI president and co-founder, smiles while boarding an elevator as seen through a window at the Ronald V. Dellums US Courthouse in Oakland, California, during the OpenAI vs. Musk trial on April 29, 2026. Billionaire Elon Musk took the stand April 28 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. The legal clash across the bay from San Francisco is widely seen as a battle of egos pitting the world's richest person against a startup Musk once backed and now trails in the booming AI sector. (Photo by Karl Mondon / AFP via Getty Images)