Card security

I think this has some consequences for Britain's ID card proposals, among other things:

The Dutch RFID public transit card, which has already cost the government $2B -- no, that's not a typo -- has been hacked even before it has been deployed

Click through and read the comments. It seems London's Oyster card uses the same technology.

But the more general point is that cards of any kind are risks to, and not protection of, data.