droid714 wrote:
sfcityduck wrote:

Whether such conduct is legal or ethical is a debate I'm not interested in, but I believe that Ms. Buscema's statement of her opinion of the situation is not actionable.

You certainly know more about the law than I do, but Courtney Love recently settled a lawsuit for $430,000 for calling her clothing designer "a nasty lying hosebag thief" and accusing her of being a drug addict and a prostitute, on Twitter.

Admittedly, that's a bit more harsh than simply calling someone a "crook" in a public forum; but calling them "crooks" in this particular forum could certainly have a negative impact on book sales.
  
Defamation requires a misstatement of fact, not merely a statement of opinion.  I suspect that Love's counsel was more worried about the allegations of "prostitution" and "drug addiction," than the more general insults.  IMHO calling someone a "crook" is far closer to saying they are "nasty" than making the factual assertion they are a "drug addict" or a "prostitute" (if not used in the allegorical sense).  The issue not "negative impact on book sales," but whether the statement is merely protected opinion (or, as an affirmative defense, true).