It never bothered me giving a thumb print. It’s not that hard to make a fake drivers license to match a stolen credit card. If someone did steal my card and I disputed the charge it’s a quick easy way for me to prove it wasn’t me. It also makes it easy for Sheri’s to prove I was present if I later try to dispute the charges. Once they prove I was there my ability to win a dispute is basically zero. The reason it’s done is it protects everyone. Protects me from people misusing my card and protects Sheri’s from people trying to cheat the ladies and them. Honestly what does it matter if they take a copy? You leave it behind everywhere you go anyway.