Spot on!
While not necessarily biometrics, a lot of stores will also use shoes to aid in tracking people.
wait what?
Was there like substantial evidence about this tjat was discovered or something?
So a lot of stores early on adopted RFID systems for loss detection/prevention, but this required the store at some point in their chain actually attaching tags to the items.
The shoe companies however decided to just place standardized RFID tags in the soles of their shoes to make this process easier.
The store systems can just register it without somebody actually having to attach a tag.
Later on they realized since these are never removed that they can use them for tracking and so it was.
You can non-destructively destroy the tags by placing them briefly on an inductive stove top. If you don’t have one you can buy a portable one for like $40.
edit: these are also common in regular clothing (in which they’re called textile tags), but those can be easily cut out
edit 2: here is a company advertising their tags for use in shoes: How to take the first steps in RFID tagging for footwear - Checkpoint Systems - RFID and RF Technology solutions
The Vortex inlay is usually used in adult footwear sizes.
and to clarify they’re actually in the shoes:
Don’t place the inlay where it might get bent through try-ons or wear.
ie. it really should be in the sole
Interesting! Didn’t know about that.