Using facial recognition to support payments is being tested in Spain, Denmark, and Canada. In China, it has already moved into deployments. More than 100 million people there have registered their faces to enable initiating payments in retail stores, at vending machines, and for mass transit. That number combines voluntary opt-in with results of a year-old national law that requires everyone who does business with a mobile network operator to have their face scanned. More than 1,000 7-Eleven stores in China use facial recognition to support payments. Customers download Alipay or WeChat Pay...