There has to be a clever way of doing this that isn’t super invasive. Having businesses record their customers and retain the only copy seems like a good compromise except something like personal phone numbers would be abused.
Maybe best would be something identifiable only to the authorities but recorded and held only by businesses. Something like driver’s license date of issuance and first name. In theory that would be meaningless to my local coffee shop or grocer; but if I tested positive contact tracers could go there and get that info (maybe just the day of my visit, or afternoon, etc.) and then correlate and contact others who visited during that time.
Maybe best would be something identifiable only to the authorities but recorded and held only by businesses. Something like driver’s license date of issuance and first name. In theory that would be meaningless to my local coffee shop or grocer; but if I tested positive contact tracers could go there and get that info (maybe just the day of my visit, or afternoon, etc.) and then correlate and contact others who visited during that time.