I seem to remember back before the days of Digital PCS when it really was actual Cellular Phones, a company (I can't remember their name) developed a cellular blocking device that was marketed to movie theaters, supermarkets, and general public areas. The various cellular companies got together and petitioned the FCC for the banning of these devices because they blocked people from making Emergency 911 calls which was considered Illegal. So when did it become ok for BART to disrupt peoples ability to make Emergency 911 Calls?

We should do the same thing we did at the end of prohibition when the government was broke and decided legalising and taxing alcohol would balance their budgets. Take a substance that the US Government ruled to be illegal to use (say Marijuana), that has a large base of illegal users, and then make it legitimate, tax it, and regulate its use to mitigate any safety concerns. It's a double whammy, you cut down on your DEA expenses fighting it and you reap the benefits of taxing it's users.

you obviously have no clue what the reality of sales point security is really like in modern retail.

The person standing next to your NFC reader and taking money only makes at most 8 bucks an hour and only gets fired if the till is off, they can just as easily put a reader under the counter unnoticed and use the data it scans later somewhere else when you won't have any idea where it got stolen from unless they get caught in the act of using it. The reason you trust clerks with swipe credit cards is because you generally get to swipe it yourself and you can see what your swiping into with NFC you can't guarantee that your info isn't being copied remotely every-time you use it.

my point was that your data can be copied while it's being used for a legitimate purchase, so you'd have already allowed activation, and all the RF capture device does is sniff the info not interact with the card.

I think it's a safe bet that most non-geek military types won't figure out how to implement this because they are too busy watching unblocked porn sites

The problem won't be turning it off while your not using it but one of it being stolen simply by using it. In a way similar to how they dupe peoples cards at ATMs you could put a RF capture device close to one of those NFC readers that can listen to the transmissions and responses then use that info to mimic the NFC device some time later. A lot of the NFC devices in phones will only work with most NFC readers in "Card Emulation Mode" which makes them as easy to dupe as any passive RFID.

I'd be interested in seeing how this car holds up to real life extreme situations like black ice on a freeway in heavy traffic at high speed when the cars around it start spinning out of control.