Careful. That's the first step toward a National ID card.
so what. we need a national ID card. if having a strong encryption social security card, was a central policy towards employer sanctions for those that hire illegals - I'd take it. the government already knows tons of information about you, an improved social security with tight security wouldn't mean anything, except for the "black helicopter" crowd.
That is the problem of course. The ACLU will pitch a fit if only foreigners are bio-identified.