This is one of those really nasty, convoluted issues that comes up with almost disconcerting regularity. Then the ACLU steps in to defend the persons first amendment rights and everyone screams about the ACLU supporting pedophilia/hate crime/pornography/ad infinitum.
First, let me state that I do not agree with pedophilia at all. Or, perhaps it would be better to say I don't agree with people that act on such. If someone has problems, let them find help, but if they never act on it, no crime has been committed.
Do I have a problem with someone writing a book like this? A text that could be taken by many as a book encouraging people towards illegal/immoral behavior? Not at all. Then again, I have no problems with the Anarchist Cookbook or it's ilk, either.
Far worse documents have been around for millenia. How about a text that advocates slavery, murder and genocide? That goes on for perhaps hundreds of pages on such topics? Would you ban the bible from bookstores for having content questionable to modern sensibilities?
In the end, is the publishing of this book actually going to push anyone to commit a crime that they weren't already intent on committing in the first place? I don't think so. Is it going to prevent them from being prosecuted, all other aspects being equal? Again, I don't think so. In all likelihood, the presence of the book itself could be admitted as evidence in court regarding the persons intent, much as owning child pornography would be admitted for showing a history or a predilection.
The particular material involved tends to attract more attention than others, but in the end it comes to a question of what information is considered such as to be censored/controlled versus what is socially acceptable.
No, I don't agree with the topic material.
No, I won't buy or even read the book.
No, I won't say that others shouldn't be allowed to read it.