If you want to start on a condescending note you should be prepared.
Passive RFID is limited to a few meters. So, if you have agents on three sides of your car they can find you in it.
Incorrect. They've gotten a return past 70 feet at hacking conventions just to show they can.
The secret is...(gasp) using a completely nonstandard high-powered transciever that they made themselves.
Passive RFID is limited to a few meters if you use a legal, commercially available reader, yes. But THEY BROKE THE RULES!
As if bad guys wouldn't do the same.
You could simply start placing reading stations at strategic points that would read every card that passed within range and then send that information to a central data base that could then plot your movements.
That's already well past the planning stage, and marketers are drooling about it. Articles have been featured in Advertising Age. The way it would work in product RFIDs would be, basically:
1. Items like shirts have a grain-of-sand RFID in the hem, a phone or other device has one built in in the plastic casing.
2. The RFID's unique ID is linked to the purchaser's credit card information at the point of sale.
3. Readers are placed in mall entry arches, kiosks, airports, and other locales.
4. Readers bounce a signal off the passive RFIDs.
5. Reader logs movement of that particular model or style of clothing for sale to marketing groups.
6. Nearby video and other displays may subtly change their next advertisement to appeal to the person wearing that shirt or carrying that phone.
And, of course, if it's linked to the credit card, you have a unique identifier that can track you anywhere, and that info could be taken for anything for a divorce proceeding to a civil or legal action, if they wanted to.