I remember an episode of Nova some years ago...
where they brought in a group of experts and systematically shredded the book, "Chariots of the Gods." They took the book apart issue by issue and did a very effective job. I can appreciate how scientists don't want to appear to give the hoaxsters any credibility. However, their silence just allows the hoaxsters to lure and rip off the gullible. Studies have shown the terrible state of scientific education in America. Letting the hoaxsters off scott free just contributes to this sorry situation.