RFID has a range of no more than 3 or 4 feet. It's not a "tracking mechanism" and anyone who tells you it is is a few bubbles off of plum.
Wouldn't it have been nice, however, if Mohammed Atta, with his 6 different legal drivers licenses, had been detected by an RFID scanner as he tried to board the airplane on 9/11?
"Excuse me sir, but why am I picking up 6 different identities and 6 different addresses when you walk past the scanner? And only one of them matches the name and address on your ticket. Hmmmmmmm?"
RFID?
Its simple to wrap the card in tin foil to disable it.
CLOSE THE BORDERS AND START THE WITCH-HUNTS INSTEAD.