Thanks for this interesting piece of news, Praetorian. So the virtual fence does not work as planned, however the government will accept and pay the contractor for it anyway. Way to go wasting our tax dollars.
But, there's a good thing about the fence being virtual - it doesn't give illegal entrants the opportunity to string thin wire on the fence that decapitates CPB officers on ATVs. Plus, if the virtual fence would actually work, it couldn't be as easily defeated as a real fence (with a ladder).
Anyway, tougher employer sanctions for unauthorized employment would probably be more effective than any fence. That, and if the government can actually devise a system to figure out who its own citizens are.