Then make it both unique and worthless. Every other country has national ids, and you gain nothing by stealing it, you actually present it almost everywhere, same value as a driver's license. In fact, when pulled over, you are asked for the license and the card, to make sure the license is really yours. What you cannot definitely do is transact with only your nacional id, that's silly. Its identification, not authentication. Your pins, passwords, signatures, presence are required in addition to your ID number to do anything. While in the US, I always thought it was weird the importance that such a document was given, to the point that even laminating it is taboo, complete with a notice written on it. They tell you to not walk around with it. Never understood how it got to this point.