GCHQ's director has said artificial intelligence software could have a profound impact on the way it operates, from spotting otherwise missed clues to thwart terror plots to better identifying the sources of fake news and computer viruses. Jeremy Fleming's remarks came as the spy agency prepared to publish a rare paper on Thursday defending its use of machine-learning technology to placate critics concerned about its bulk surveillance activities. "AI, like so many technologies, offers great promise for society, prosperity and security. Its impact on GCHQ is equally profound," he said. "While this unprecedented technological evolution comes with great opportunity, it also poses significant ethical challenges for all of society, including GCHQ." AI is considered controversial because it relies on computer algorithms to make decisions based on patterns found in data.