We have linked our POS software to our security system and can easily track who purchased what and when if the store owner wishes? This enables easy checking in the event of a dispute over a refund or change given. With appropriate signs in in the shop I see no problem with this. The same technology can be used to track who enters the shop. This information cold be used for more than traditional theft management purposes and it’s where I have ethical questions? What if the images are being used to track people protesting against your business? What if you’re involved, somehow, in racial profiling? What if there is a more sinister purpose to you capturing images of browsers as well as those who purchase products? My feeling is that the store owner would need to disclose such behavior and to make the data available to any customer seeking access to their records. I’m interested because it’s been suggested to me that at least one major retailer is testing face recognition software for scanning people entering its retail locations.