I seem to remember a post on some subreddit or forum obsessed with data privacy, where a guy was freaking out that when he was ID'd at a restaurant, the waitress put his ID into a machine that scanned it. He was convinced it was entered into some sort of database or cloud service and demanded to know how they were handling his data or who they were giving it to. He was very irritated that the restaurant staff didn't seem to understand what he was talking about or what he was getting upset about.
Now that I'm working a position where we ID people for the first time in my life, I understand. There is no database or cloud service. We can scan the barcode on the back of any USA ID card. The data in that barcode is just a copy of what's printed in plain text on the front of the card. All the computer does is parse that block of info for the date of birth and check it against "is this date over or under 21 years old."
Like, I could easily imagine a customer being enraged that I scanned the back of their ID because that feels like a shady thing to do, but really it's just typing in your birthdate faster than my hands can. That's the extent.
