OK, so with all the talk about RFID privacy, isn't it time to take a moment to contemplate the physical security of the RFID tag itself. Consider for a moment the hypothetical situation that your friendly neighborhood Wal-Mart has RFID tags on every product. What is to stop you from:
a) taking one of these into the store plugged into your PDA, walking through the aisles, and in about 10 minutes having an exact SKU by SKU inventory count for the store? (Remember, ePC is standards-based, so the same tag means the same thing in every store...)
b) taking one of these into the store, and walking through selectively (or indiscriminately, for that matter) zapping RFID tags on products, thus rendering the entire RFID-based check-out and security system inoperable and causing all the affected tags to have to be identified and replaced? (This form of sabotage would be EASY... responding to consumer pressure, the Metro Future Store installed an RFID-tag de-activator outside the checkout... why couldn't you simply do the same thing in the store?)
Consumer-facing RFID needs a little more thinking before it becomes mainstream.