These books, although they may be loaded with misinformation, are not illegal.
If the government was powerless to do anything about the infamous "Anarchist's Cookbook", which was packed with recipes for bombs and drugs that were (intentionally?) incorrect and likely to injure/kill the reader if actually used, do you really think that the government is could really pull DIY home wiring books off the market?
And we shouldn't wish it any other way. The First Amendment is a wonderful thing...
Maybe the DIY books should just be relegated to the fiction aisle.
I imagine the publishers have a disclaimer in these books that gets them off the legal hook. All they really have to say is "your local codes may vary, check with your building department" or words to that effect.
You don't have to take courses or use DIY books. All the instruction you need is here on this here internet!! And as you all know, all the information on the net is accurate and truthful! You should of heard my sound system before I bought a $90 audio grade receptacle and $15 a ft oxygen free wire fo the speakers. Man what a difference!! i would have never known if I had not read it on the net!!
The single most egregious DIY artwork I've seen is Reader's Digest's [ISBN 0-89577-378-3] -- pages 252 & 253:
Repeatedly the switch-leg in Romex is color-banded white.
Illustration #2 shows Romex leaving the box as TWO neutrals, one banded, and popping out as black, white, bare-ground!
This banded-switch-leg notion appears in many other DIY efforts, too. I just don't have them ready-to-hand.
If errors this glaring populate the electricity section one can only fear for those trusting the foundations and framing instructions.
The book is advertised by one on-line retailer as, "The most complete and authoritative home repair manual ever published, this book is the yard-stick by which all other books on do-it-yourself are measured. The definitive guide to home repair, maintenance, and improvement. Over 4,000 illustrations."