Thanks for bringing this up. Yes, ALWAYS watch the items being rung up-they are frequently rung wrong(say THAT fast 3 times) And if you're in the grocery store, make sure to remove the coupons from the items if there are any and give it to the checker-otherwise, they are not used!
Fast food drive thrus too - how many times have you been shorted, or overcharged?
Here is another - just happened to me AGAIN recently-------When you charge something on your credit card, write down the date, store, and charge. My "D" card was compromised several times, first a small amount, then larger...and larger. Thank goodness I got my $200 back and can't trust ANYONE!