Panera Bread trials Amazon's palm-scanning tech in St. Louis.

Panera Bread is testing Amazon's palm-scanning technology in two of its St. Louis restaurants to offer customers a faster way to connect to their loyalty program and pay. The bakery-cafe chain plans to expand the test to 10 to 20 more restaurants over the next few months. However, Amazon has faced backlash from consumers and privacy experts for its use of biometrics, which use biological measurements to identify someone. Despite this, Panera chose Amazon's technology because it's contactless, customers have to opt in, and a person can't be identified by their palm alone.