Interesting, to be sure. I'm against the idea of the government tracking more info about me, though. While I realize that many different companies out there have all sorts of info about me, this would move it to the government having a legitimate need to track that info.

With that in mind, a simple driver's license seems to work well. Demonstrating that someone's had a DL for years and at least resembles their picture is a reasonable precaution. The swiss cheese (or interference screen) concept is certainly good, though. Foreign national, paid cash, etc? That's a checking. Born in the US, over 35, used the same CC you've been using for years, etc? That's a pass.