RFID Security

Privacy advocates are worried that RFID in passports will start open season on identity theft. Addressing the concerns from the commenters (warning: IANAHO/SG I am not a ham operator / signals geek):

RFID can be snooped like any radio device using a strong directional antennae. But, the signal is extremely weak and broadcasting only reflections of external radio waves – so weak that wrapping an RFID device in tin foil is enough to defeat the snoopers. Designing a physical passport token defaulting to a closed state via a spring, slide, fold or other mechanical means is trivial and closes the security loophole in the same way your wallet keeps thieves from getting your driver’s license and credit card numbers using strong optical photographic means.

Am I on the wrong track here?