A single ID card needs to be issued. No need to issue multiple documents and cards to the same person.
A secret serial number (encrypted) on the card which connects it to the right database entry. No way to duplicate or forge this.A single fake document can no longer be used to generate other perfectly legal documents.
For example today many criminals start with one fake document (say a Social Security ID card) and using that as the identifier, apply and get other perfectly legal documents like passports, driving licenses and the like. This will not be possible in an RFID based system.
Instant snapshot data of the population. No need to painstakingly conduct surveys or mine data on demographics, population behaviour, age profiles, etc. This is especially useful for governments to plan their spending.
