Posters do not seem to understand the difference between RFID tags and the current scan tags on merchandise. With RFID tags you do not have to pass each item over a scanner and wait for it to match. You can literally bring your cart to a spot and it will know what is in your cart. If you choose not to use a cart, you set your items on the table. It will know what items you have and the cost of those items.
They will not need those "inky things" as a poster put it. If you try to take an unpaid for item out of the store, the RFID tag will set off the door alarm.
As for power outages? Guess what, with the current system in the event of a power outage they can't sell anything either. The cash registers won't do the math and they won't open without power. Not to mention the credit/debit machines not working.
Everyone is jumping on the why it can't be done or why it is a bad idea train. No one is wanting to give it a chance or try it. RFID tags are one of the best things invented for inventories. People tend to resist change. There will be others that will love being able to simply walk up to a counter, set their items on it, swipe their card and be on their merry way.
Imagine how much time it would save in a grocery store if the cart knew what your total was for all items in the cart? Take an item out and it comes off the total, put an item in and it adds to the total. RFID tags do not have to be scanned. They read by Radio Frequency. It is a wireless non-contact system. It does not have to pass within sight of a scanner. It is so small that you won't even see this little device. Hitachi makes an RFID chip that is .05 mm x .05 mm. Hundreds of RFID tags would be read simultaneously. Unlike a bar code which has to read, one by one. Passive RFID which is what they would be using cost between 3¢ and 5¢.