Years ago, when I lived in California, I'd go to the grocery store nearly every day. I usually paid by check. Each time, the clerk would ask me for my phone number and then write it on the check.

When I ran out of checks, I decided to be clever and had my phone number printed on them. You guessed it, without missing a beat, that same clerk started asking me for my driver's license number (and yes, I did it one more time, and we moved on to my social security number).

The information wasn't the point. It was the asking, the time taken to look closely at the document.

http://sethgodin.typepad.com/seths_blog/2016/04/just-a-little-more.html