Elon Musk is threatening to sue Microsoft after accusing the company of illegally using Twitter data for training purposes. The Twitter CEO made the bizarre claim in reaction to the news of Microsoft’s advertising platform dropping support for Twitter starting on April 25 (via Techcrunch).

Microsoft quietly announced on a support page that its “Smart Campaigns with Multi-platform” ad product would no longer support Twitter later this month. This is likely related to Twitter’s decision to charge companies using its Enterprise API a minimum of $42,000/month based on usage and needs.

Anyway, this prompted a swift response from Musk. “They trained illegally using Twitter data. Lawsuit time,” the Twitter CEO tweeted.

They trained illegally using Twitter data. Lawsuit time.

— Elon Musk (@elonmusk) April 19, 2023

In a separate tweet, Musk said that he was open to alternative solutions for monetizing access to Twitter’s data. “I’m open to ideas, but ripping off the Twitter database, demonetizing it (removing ads) and then selling our data to others isn’t a winning solution,” Musk tweeted.

Musk’s original tweet also does imply that Microsoft’s new AI tools used Twitter data for training purposes. The company’s Bing chatbot is powered by OpenAI’s GPT-4 technology, a company that received a multi-billion dollar investment from Microsoft. OpenAI says that GPT-4 was “trained using publicly available data (such as internet data) as well as data we’ve licensed.”

As you may know, Musk co-founded OpenAI before leaving the company a couple of years later. According to the Wall Street Journal, the Twitter CEO recently launched a new AI startup named X.AI that may soon compete with OpenAI. While it’s too early to say if Musk’s lawsuit threat should be taken seriously, what the Twitter CEO tweeted likely isn’t the full story.