I have noted and questioned the efficiency of receipt\cart comparison as I leave and show my receipt at Sam's. I can have 10 items spread out in cart and employee will check two or three items. Then I see overflowing carts that get same treatment. Not hard to see inappropriateness of this procedure.
I totally understand how things can easily walk out of stores like this, especially with push to self checkout. Sad but true.
Oh. They no longer put line through receipts.