Aside from the issue of the original author not receiving payment, counterfeit books can actually have textual errors as well. A few years ago when the 3rd edition of The Art Of Electronics was published, I saw quite a few warnings posted online not to buy from Amazon. These counterfeits were poorly printed and had many typographical errors, many of which made the information factually incorrect and caused that specific copy to be untrustworthy. So especially for a reference text like that, a counterfeit can actually cause harm if the information isn't correct.