So as silly as the post looked, benjamindees made a good point.
"Request private key!" A long range nfc reader (hah, far field?) could be a security issue.
I've heard
recent stories from the UK, saying nfc payment systems are reading cards accidentally (at longer ranges than intended). Clearly if this can happen accidentally, there's the possibility for this kind of attack to made deliberately.
See the Q & A section of the Firmcoin page:
Q8. What stops me walking past someone holding one of these and stealing all their money?A8. The Firmcoin has two capacitive buttons. You have to press only one to redeem the private key. If you press both, then the private key cannot be retrieved for a few seconds.