What should a consumer do once they realize they have been taken by such a scam?
That's tough. Many times a homeowner has already given over money or signed paperwork that they were fraudulently induced to sign. If money has changed hands, the chances of recovering it are slim.
A complaint should be made with the local police department or at the local District Attorney's office. If somebody was induced to sign fraudulent loan transfer papers, they might consult someone at their local county recorder's office about possible remedies for them. But time can be of the essence as scammers will quickly try to resell a house that has been taken from a homeowner via fraudulent means. I think the recourse is pretty limited. Some criminals will get caught, prosecuted, and incarcerated, but many more will never get caught.