A massive global technology outage on Friday took down airlines, medical services, TV broadcasts, banks and scores of other business and services around the world, a stunning example of the fragile dependence the global economy has on certain software and the cascading effect it can have when things go wrong. The outage was attributed to CrowdStrike, a cybersecurity firm whose software is used by scores of industries around the world to protect against hackers and outside breaches. A...