STORY: Elon Musk has joined artificial intelligence experts and industry executives worried about AI's impact on society.He is among signatories to an open letter calling for a six-month pause in developing systems stronger than OpenAI's GPT-4.The letter was issued by the non-profit Future of Life institute, and signed by more than 1,000 people.They have called for a pause in advanced AI development until shared safety rules for it are developed, implemented and audited by independent experts.The letter said 'powerful AI systems' should be developed only once the effects are likely positive, and the risk manageable.It listed potential threats from competitive AI systems in the form of economic and political disruptions.Tesla CEO Musk was one of the signatories, along with Apple co-founder Steve Wozniak and researchers at Alphabet-owned DeepMind and other AI heavyweights.The Future of Life institute is mainly funded by the Musk Foundation, according to the EU's transparency registers.Though Tesla uses artificial intelligence for an autopilot system, Musk has been vocal about his concerns over AI.On Monday, EU police force Europol warned about the potential misuse of the system in cybercrime and disinformation.The UK government also unveiled proposals for an 'adaptable' regulatory framework around AI.Since Microsoft-backed OpenAI launched ChatGPT last year, rivals have moved quickly to develop similar models.OpenAI didn't immediately respond to request for comment about the letter.