Twitter accuses Microsoft of unauthorized data usage.

Twitter has accused Microsoft of using its data in unauthorized ways and violating multiple provisions of its agreement with Twitter over data use. The letter from Twitter's attorney to Microsoft CEO Satya Nadella and the company's board stated that Microsoft declined to pay even a discounted rate for continued access to Twitter's APIs and content. The rift highlights the growing debate over who owns data that can be used to train artificial intelligence and machine learning software.