The Claude chatbot from Anthropic has claimed the top spot among free apps in the US App Store, pushing OpenAI’s ChatGPT to second place.
The change in leadership was driven by a mass exodus of ChatGPT users. Earlier, OpenAI CEO Sam Altman announced a collaboration with the US Department of Defense, agreeing to deploy its AI models in classified military networks.
Tonight, we reached an agreement with the Department of War to deploy our models in their classified network.
In all of our interactions, the DoW displayed a deep respect for safety and a desire to partner to achieve the best possible outcome.
AI safety and wide distribution of…
— Sam Altman (@sama) February 28, 2026
Anthropic CEO Dario Amodei publicly refused such contracts. He prohibited the government from using the developer’s neural networks for mass surveillance and autonomous weapon creation.
US President Donald Trump criticised Anthropic’s decision, accusing the team of attempting to dictate terms to the defense department. Subsequently, the Pentagon terminated contracts with the company and blacklisted it as a “national security threat.” Within hours, OpenAI secured the military contract.
The company’s decision sparked a backlash in the community. A post on Reddit calling for a boycott of the chatbot garnered 30,000 likes, while the themed Instagram account quitGPT attracted 78,000 followers.
More than 700 employees from Google and OpenAI also signed an open letter. The document urged the rejection of AI use in surveillance systems or for combat tasks without direct human oversight.
Outside Anthropic’s office in SF… intense moment! pic.twitter.com/8uBPfZi0nc
— Roy E. Bahat (@roybahat) February 27, 2026
An Anthropic representative told Mashable that since January, the service’s free user base has grown by 60%, and the number of paid subscribers has doubled. Meanwhile, the daily number of new registrations has tripled.
In February, it was revealed that SpaceX was involved in a Pentagon project to develop voice-controlled autonomous drones.