 We know that Microsoft says it's investigating an incident to do with its U.S. cloud service. And there's a company called CrowdStrike, which does antivirus software, if you like. And there are lots of reports suggesting that it has issued an antivirus update that has gone horribly wrong. Here in the U.S., the website DownDetector reports growing outages at Visa, ADT Security, Amazon, American and Delta Airlines.