Actually, approximately 40% of illegals are entered into a system already, because they arrived legally and overstayed their visa. Those are the people Christie is talking about - the idea is that with better systems to keep track of people here on temporary visas, it would be easier to prevent overstays.
Up until some time in the early 70’s. green card holders, that’s all with legal status permanent, temp student or work, had to register every January with a Feb cutoff date. Information included residence address, phone, all employment info. Radio, TV, newspaper ads started appearing after first of the year as reminders. Every US Post Office had the necessary card forms.
Seemed to work pretty well in pre-computer era until they “fixed” it.
But you know they wouldn't stop at only tagging illegals. They'd just use them as beta testers to work out all the technical issues so they could tag everyone else.