Billionaire Elon Musk said on Monday he would ban Apple devices at his companies if the iPhone maker integrates OpenAI at the operating system level. "That is an unacceptable security violation," Musk, who is the CEO of electric-vehicle maker Tesla and rocket maker SpaceX and owner of social media company X, said in a post on X. "And visitors will have to check their Apple devices at the door, where they will be stored in a Faraday cage," he said.