An attendee checks his mobile phone while standing next to a poster of a model wearing the Microsoft Corp. HoloLens augmented reality (AR) viewer at the Microsoft Developers Build Conference in San Francisco, California, U.S., on Thursday, March 31, 2016. Microsoft Chief Executive Officer Satya Nadella said his company is committed to playing a key role in the emerging market for artificial intelligence-based chat software, one week after the company's first Internet chat bot in the U.S. was so manipulated by users that it had to be pulled down within a day of its introduction. Photographer: David Paul Morris/Bloomberg via Getty Images