Could Americans tell if they are being "Tracked"?

Could Americans tell if they are being "Tracked"?

Everyone's so paranoid about the RFID chips that are already in place in so many parts of our lives, so here's an item (via Engadget and Pink Tentacle) about Hitachi's new powder-sized RFID chips to make us even more scared of Big Brother (or little-Brother-ID thief). RFID chips are tiny microchips that use radio waves to do everything from conduct credit card transactions (as on those little key-fob-Paypass MasterCard thingies) and pay for tolls (EZ Pass and its ilk) to keeping track of your devices and travel (U.S. passports).
Hitachi plans to start marketing these new chips—seriously no bigger than a speck of dust at 0.05 x 0.05 mm—in two to three years. The company says this super-tiny chip can be used in paper, currency, gift certificates, and the like, but as some sites have pointed out, today's chips are already small enough for those uses. So, as Engadget cracked, does this mean we should be watching what we eat in case of some James-Bond-style pepper-shaker swap?