Garth told me that at Gritscone, the bolts were placed with very little thread above the nut, making it very difficult to theft-proof the hangers. If it happens again, the bolts will be replaced with longer ones.
Almost everyone I've spoken with agrees. The thing to do is to e-mail the guidebook author and tell him what you think they ought to be (Garth at info@northbendrock.com). I'm sure he'll be coming out with a revised edition at some time in the future. Perhaps he might even publish an addendum online that could be printed out for free. I'll bet he would.