Elon Musk and Sam Altman have renewed their billionaire brawl as both seek to sell investors on their own vision of the AI revolution.

The longstanding feud between the OpenAI cofounders reignited over the weekend when the world’s richest man chimed in about Apple’s lawsuit against OpenAI.

On Friday, Apple sued OpenAI and two former Apple employees who joined the AI startup, alleging they stole company secrets to help build up OpenAI’s hardware business. OpenAI has denied the claims, telling multiple outlets it “has no interest in other companies’ trade secrets.”

Musk pounced on the Apple news to lambast Altman. “Scam Altman strikes again,” Musk wrote, reviving a Trumpian nickname he has previously used to describe the OpenAI CEO. Over the next day, the SpaceX chief doubled down, replying to several other posts with put-downs like “He takes scamming to a whole new level” and “He might literally love scamming more than any human alive!”

Altman shot back in a reply on X Saturday in which he claimed Musk is “the one sellling [sic] public market investors on short-term space datacenters.”