In recent years, Musk has filed no less than four different lawsuits against OpenAI, many of which have since been dropped or dismissed. This one, though, names Altman, Brockman, Microsoft, and OpenAI itself as defendants, and it has made it to jury trial in a California federal courtroom. It’s expected to draw testimony from AI industry leaders, including Microsoft CEO Satya Nadella, Microsoft CTO Kevin Scott, and former OpenAI CTO Mira Murati (who is now the founder of her own AI company, Thinking Machines Lab).

The crux of the suit alleges that OpenAI violated its core mission to build AGI, or artificial general intelligence, that benefits all of humanity, and it also makes allegations of potential fraud, unjust enrichment, and breach of OpenAI’s charitable trust. Musk is calling for the court “to strip Sam Altman and Greg Brockman of their positions of authority and the personal financial benefits they extracted from OpenAI’s illicit for-profit operations and conversion” and to unwind OpenAI’s for-profit restructuring, among other things.

Correction, May 4th: Altman, Brockman, Microsoft, and OpenAI were listed as defendants, not plaintiffs, as this story initially misstated.