ID card is not needed. There is no reason to hold one since they already have access to your data, and authenticate by your picture and other. Using a card just allows more fraud crimes, something that is already very bad in the US.
When I traveled to Saudi Arabia a few years ago they took my fingerprints at customs. When exiting the country, I didn't give them my passport - they just scanned my thumbs and asked me to confirm my name.
