Anthropic sued business partner and competitor Abnormal AI, accusing the company of adopting a logo and branding confusingly similar to Anthropic's visual identity. The San Francisco-based frontier artificial intelligence lab said it increasingly competes with Las Vegas-based Abnormal on AI security products and services, and offered Abnormal time to transition to a different logo, but Abnormal declined. Abnormal said its branding predates the timeline alleged by Anthropic, and that no customer has ever purchased Abnormal's products believing they were buying from Anthropic. "This case arises from Abnormal's efforts to rebrand itself around Anthropic's distinctive commercial identity while competing in the same market for AI-powered enterprise security where Anthropic has already built substantial goodwill under its marks," Anthropic wrote in a 31-page complaint filed July 1 in U.S. District Court for the Northern District of California. Abnormal CEO Evan Reiser said Anthropic's lawsuit came as a big surprise since he is a major user and advocate, saying in a blog posted Tuesday he expects to spend $1 million from his personal Anthropic account this year while Abnormal as a whole will spend more than $10 million. Most companies decline to speak about ongoing litigation outside court filings, making Reiser's blog and LinkedIn post unusual. "We're a very large customer of Anthropic and they still have yet to tell us about the lawsuit," Reiser wrote. Despite Abnormal being a big user of Anthropic, the two companies don't appear to have deep technical ties; Abnormal hasn't