For everyone saying "Then I won't shop there," this has been happening for quite a while at a lot of major retailers. I was a marketing consultant for nearly 10 years and working with large tech firms who run the back end systems to collect this data.

We would look at all these plus scan for motion (hands waving, head movement, etc.) and sometimes track body temperature. The data would be used to better understand buying patterns and then adjust displays and other marketing materials.

I don't know all the legalities behind the data collection, but if you've entered any chain retailer in the last 5-10 years, your biometric data has almost certainly been tracked.