Elon Musk testified that OpenAI CEO Sam Altman “stole a charity” and was endangering the world by racing toward powerful AI, highlighting the two men’s deep personal animus.

Musk cofounded OpenAI as a nonprofit dedicated to creating safe AI, but Altman later launched a for-profit subsidiary and is now gearing up for an IPO. The Tesla boss alleges that OpenAI is in breach of its mission.

If successful, the case could cost OpenAI $130 billion and force it to undo its restructure. OpenAI says Musk is “motivated by jealousy.” Altman’s rivalry with Musk is one among several in Silicon Valley; the OpenAI boss famously refused to hold hands with his Anthropic counterpart at a recent AI event in India.