A lawyer for Twitter owner Elon Musk accused Microsoft of misusing the service's data and demanded an audit from the software giant. The letter primarily addresses a seemingly narrow set of alleged infractions by Microsoft in drawing information from Twitter's database of tweets. But the move could foreshadow more serious developments.

Musk has previously accused Microsoft and its partner OpenAI in a tweet of "illegally" using Twitter data to develop sophisticated AI systems such as ChatGPT. "Lawsuit time," Musk wrote in that April tweet. But the letter, signed by Musk lawyer Alex Spiro, tiptoed around that concern. It noted that Microsoft's agreement with Twitter barred it from overuse of the service's data such as exceeding "reasonable request volume" or "excessive or abusive usage."