@hightor,
You don't like new technologies??
How about some old technologies, like land mines and machineguns? If you did it just a little bit intelligently, you could pretty much guarantee that nobody wold ever cross the border illegally.
Aside from the giant monetary savings, that would put our immigration policies on a rational basis so that people in the world who really do need a place to come to might have one, i.e. our entire immigration system wouldn't be in a permanent state of being swamped by a demokkkrat scheme to import voting blocks for themselves.