Just want to share a little story.
Purchased a small banana pudding yesterday. The cashier lady said $4.25 and as I was ready to swipe the credit card on the screen, I noticed that the cashier had quickly added $1.50 tip to the price without saying anything making the total price to be $5.75. Good thing I caught that. I undid the tip and paid. I consider that as cheating and thinking about sending an email to the company. I am sure a lot of people do not notice this when they are paying with credit cards.