https://arstechnica.com/tech-policy/2023/07/musk-and-zuck-may-fight-in-court-twitter-threatens-to-sue-meta-over-threads/

The proposed cage match between Elon Musk and Mark Zuckerberg might never happen, but the tech titans may soon battle in a more civil arena. Musk's X Corp., the successor company to Twitter, yesterday threatened to sue Meta over alleged intellectual property violations in Meta's new Threads social network.

Musk's lawyer Alex Spiro wrote a letter on behalf of X Corp. to Meta CEO Zuckerberg. "Based on recent reports regarding your recently launched 'Threads' app, Twitter has serious concerns that Meta Platforms has engaged in systematic, willful, and unlawful misappropriation of Twitter's trade secrets and other intellectual property."