 Microsoft now says about 8.5 million devices running its Windows operating system were affected by a faulty cybersecurity update Friday. The update from CrowdStrike led to worldwide disruptions in travel and business. Sally Walker is former cybersecurity director of GCHQ. It does emphasize that we live in a world of dependency and vulnerability and that disruption can and will happen. And IT is at the core of our day-to-day operations, our businesses, our economies, our communities.