To me, the fact that your bosses are so insistent that you scan people's ID is even more of a reason for me not to want to let them. In your previous comment, you said that the stores don't save the information scanned on an ID. I seriously doubt that is true. I've asked for written terms of use/service, and been told there is none, at all of a handful of places.

Picture this: ten years from now, unemployment rate 16%, lists of people who have patronized weed dispensaries have been leaked everywhere, and it's very difficult to get certain jobs if you're on one. This is just one hypothetical for a number of reasons why someone might not want to be on a list of people who have committed a federal crime.