 and from the John S. and James L. Knight Foundation, helping NPR advance journalistic excellence in the digital age. Good morning, I'm Ru Abbas at the BBC. The cybersecurity company CrowdStrike has taken responsibility for a global outage that has affected computer systems worldwide, disrupting transport, broadcasters, hospitals and other sectors. It says the outage was caused by a defect in a Windows update, as the BBC's Joe Tidy explains.