People are getting brainwashed into giving away information on the web and real life.

In the US it's not rare to link accounts through phone numbers that are required in web forms and store memberships.

In Chile they started asking for your National Id with so many stupid pretexts that people got conditioned into just giving it away. It wasn't like this 10yrs ago. I'd rather have membership numbers.

It's technically public information, so collecting Ids is legal, but it's also a universal primary key within the country that allows merging any user-related table you run into.

Retail says it's just to associate it with receipts in case you need that later, but I'd rather just get a photo of the printed receipt for later than rely on them to find my receipt. Supermarkets, Drug stores, and petrol stations tie it to (possible) discounts or points at check-out, which is price discrimination and it's illegal, but we are in our way to get surge pricing as soon as the new US bootlicker president begins his period next week.

Giving out the Ids directly is stupid. Any sane scheme would use unlinkable attestation.