Performance-monitoring wearable tech - and workers' rights

At the U.K. supermarket chain Tesco, workers wear sensor-bearing armbands to track inventory while unloading goods. "Pickers" that put together orders at Amazon.com warehouses wear GPS tags designed to guide them on the most efficient warehouse route. All of these wearable devices are designed to monitor worker productivity, combining man and machine for maximum efficiency. Wearables have been long used to help monitor an individual's health and fitness. But now wearable use is becoming increasingly common in the workplace to record, analyze and enhance worker productivity, raising concerns among lawyers and labor specialists who feel that it's a step toward stripping employees of workplace rights...