Fools rush in where angels fear to tread. The old saying seems particularly apt when discussing the issue of trolling and, more specifically it’s relationship to book reviews. For anyone unfamiliar with the term, a troll is an individual who makes comments in order to provoke conflict. Here we are not talking about a reader who provides a 1 or 2 star review and furnishes a reasoned explanation for his/her perspective on the work. Authors may not like such reviews (although one can learn from constructive criticism), however they can not be considered as constituting trolling. Everyone is entitled to their opinion and the taking of offence at the expression of opinions with which authors (or anyone else) may disagree is not a valid reason for labelling such expressions as trolling.
Genuine trolling is, however sadly alive and well on the internet. Take, for example the following review and the comments generated by it, https://www.goodreads.com/review/show/499148682. The reviewer takes a positive delight in ripping the author’s work apart. It is, to the reviewer a source of considerable hilarity to point out grammatical errors (real or imagined). He appears to revel in making his followers laugh and laugh they do in response to the reviewer’s tearing apart of the author’s work. What should be a serious forum for discussing literature degenerates into an arena in which the reviewer and his/her followers rip their quarry apart. Blood sports are banned or curtailed in many countries but they remain alive and well on the internet.
As a libertarian (with a small l) I am wary of banning activities. There is a thin line between a person expressing their strong objection to a book and an individual deliberately looking to stir up conflict for the sake of so doing. However it strikes me that forums such as Goodreads need to look at whether they have strong enough measures in place to prevent, so far as is possible, unproductive and often vicious attacks on authors.
(Disclaimer: I have not read the book in question nor am I acquainted with it’s author).