How often do you look at your store receipt? Most perchases are made with a credit card or debit check card. Once you swipe your card, there is a option of receiving 'cash back'. What most people don't know is that the cashier has the ability to chose this option for you. After you have left the counter the person in line after you (an accomplice) is handed the $20 or more dollars that has been taken off your card. On security camera, it looks like a normal day at the store counter. The only way to protect this from happening to you is... Look at your receipt before leaving the counter. Use cash.
Be aware, lots of scams intensify around the holiday season.

I don't even budge after I've received the receipt in my hands until I've looked it over. Then I move 2 steps away from the line and carefully look at every item on the receipt. It's amazing how many times I've been double rung for items even though I look at the cashier's scanning each item in front of me.

Yes, and also be aware of pick pockets roving around in stores of any kind - even junk stores are not immune to these thieves. Keep your wallet and pocketbook close. Never place your purse in the shopping cart as you are inviting them to your wallet.