RFIDs aren’t evil. At least one sushi restaurant, Pintokona, in Tokyo knows this. Every plate is embedded with an RFID tag, allowing managers to see who made it, what it 
is, how much it costs, and how long has it been sitting on the conveyor belt. Customers are billed quickly and they always know that what they’re eating is fresh.
To be honest, I don’t get the whole scare over RFID tags. They track what you purchase? So do barcodes and receipts. They can build a personal profile of what you buy? They already do that with debit cards, credit cards and frequent shopper programs like AirMiles. Afraid of getting more junkmail? Stop signing up to in-store contests and sweepstakes.
Other people can find out what and where you buy? Only if they’re within a five metre radius. And if you don’t think retailers aren’t going to encrypt their tags…well, let’s just saying making sure their competitors don’t steal their precious marketing data is about as important as maintaining your privacy to keep your business.
Perhaps the best compromise would be to have RFID tags removed upon item purchase, like anti-theft tags on clothing. This might be ideal, since RFID tags cost a lot more than a printed UPC code.
Besides, if Walmart knows you like Shampoo Brand X, maybe they’ll buy more of it. Having a greater idea of what is and what is not in stock reduces the need for stockpiling, which can translate to lower prices. RFID tags on perishables makes sure you don’t go home with a mislabelled, rotten goods. Isn’t that a good thing?