I haven't seen anyone mention what to me is the biggest issue with self-checkout, false accusations of theft. I recently went through the self-checkout line in my local grocery store and accidentally left one item behind. When I went back to the store to retrieve it, they accused me of trying to take the item without paying for it. They said the person monitoring the self-checkout lines saw me put it in the bagging area without scanning it first. I had to go back to my car and get the receipt, which clearly showed I had paid for the item, but needless to say it was unnerving being accused of theft. I always use the staffed checkout lanes now, self-checkout isn't worth the trouble.