Reply #9: Hammer works, or wrapping it in foil, or stick it in the microwave.

[meldroc]

I'm in a position to know about such things, as I work for a company that makes RFID readers.

A hammer's probably the best bet - if you feel any RFID tag, you'll feel a bump where the RFID chip is embedded - it's about the size of a pinhead. Whack it with a hammer to destroy it.

You can also wrap it in aluminum foil or aluminized mylar to block the signal. Wrap it up tight, make sure there aren't any gaps, so the foil creates a Faraday cage.

Also, if you microwave the tag, the energy from the microwaves will turn into a huge amount of electricity in the antenna due to induction - stick a CD in the microwave to see this effect at work, and enjoy the lightshow. The high voltages will fry the RFID chip, but it will likely scorch the driver's license it's embedded in (and set it on fire, and stink up your microwave,) and you might not want some cop to see that...