Presumed terrorists will start using gloves when handling things. Then one day the DHS/TSA will decide to do DNA tests on everyone entering the country. So then the terrorists will start using clean rooms to build bombs and stuff.

Eventually, some bright mind will figure out that identification doesn't mean better security because most terrorists will keep a low profile prior to the act making it near impossible to identify them on an inbound plane flight, ship, or car trip. The DHS response to that will be to close the border.

Only Hollywood and politicians believe that terrorists carry a terrorist identification card which is used whenever they buy something or check into a hotel or airplane flight.