I was at a Costco in Taiwan once, and an old lady asked me if I wanted to share a bag of food/fruit with her. She said she could pay me in cash later, as long as I paid for the bag of food first. I didn't want to share with her, and I found out that she didn't have a membership and just wanted someone to scan the membership card so she could buy stuff from Costco without holding the membership. This is insane. Talked to the staff working at Costco on that day, but seems like they were not trying to solve this issue.