Let me give you an example. Just as Congress was passing Welfare Reform the USPS was implementing a new standard called "Move Update" that involved changes of address.
If a mass mailer of First-Class Mail did not make sure he had the latest address for all the addresses on his mailing list he would have to pay the higher rate applicable to ordinary mortals rather than the substantially discounted rate given to big corporations (all with good reason mind you).
Welfare folks regularly mail stuff to welfare recipients even if the checks are transferred directly to banks where the recipients hold accounts.
Move-Update had a tool associated with it that allowed mailers to quickly access change of address orders filed back to 3 years before. It was fast, done by computer, and seemed to be something that could pay for itself almost with the first run of a list.
Well, the Welfare People had a rule running back to the establishment of the federal welfare operation in the 1930s that seemed rather innocuous and simple, but almost unenforceable. The rule required any welfare recipient to report to a case worker if he or she "changed address". Else, no welfare payment could be made.
It was claimed (or alleged, or imagined) that many welfare recipients cheated by simply qualifying at one address, moving to another and qualifying there under another name, and then moving to yet another and qualifying there. The thought was many welfare recipients were cheats who took far more than they were due.
Well, the welfare people in the various state finance departments were among the very first to use Move Update's "Fast Forward" system to get the latest addresses of the folks getting the big bucks.
Numerous states reported that sometimes MORE THAN HALF of the recipients did not qualify for payment since they had MOVED and not reported to a caseworker!
Well, the story is that Welfare Reform worked. Half the folks came off welfare and got jobs. America got better, and everybody was happier.
So, was it the magic of Welfare Reform and the smiling faces of the case workers extending new educational opportunities to recipients, or the cold hard discipline of a robot-like machine called "Fast Forward" that did the trick?
You be the judge.
Similar magic can be performed with careful application of computer power to the question of proving or disproving identification. All that's missing is an instant penalty, and that might well be the cancellation of credit cards and the freezing of bank accounts, either of the employer, the illegal, or both, and maybe those of their friends, relatives and neighbors ~ whatever it takes. It'd sure wake folks up.