Oops! A hasty addition to my prior post.
I just noticed a "Sumiko" warning on the Sonus Faber page of the Audiogon classifieds. The warning statement is more ample than the one reproduced by Sogood51 in his post. Its wording would seem not to exclude a private sale buyer who can establish that the speaker was initially bought from an authorized dealer. However, I wouldn't buy a Sonus Faber speaker on a resale unless I first got that interpretation confirmed by Sumiko in writing.
I'm of two minds on a seller having to document the origin of the item he's selling. On the one hand, it's an extra paperwork burden and punishes a seller who is not good at keeping records. On the other hand, with products that can be counterfeited, it offers some assurance of genuineness to the buyer.