Well... I have heard of authors who harass people who write bad reviews on some book websites.
I have also heard about one author who seriously stalked one of the people, who gave their book a bad review, and showed up at that person's house...
Not related to books, but I know someone personally who reviews movies, and he once wrote a review for a movie by a director from my country. And he gave that movie a 2 out of 5.
Then the husband of the director complained about the review in a Facebook post or something, I can't remember. I think that man was being like "oh my goodness, how dare this guy talk trash about that movie my wife directed?"
Well... I'm an author... kind of.
Or the only thing that I have written which has gotten published, is a short story, which was released in a collection of short stories written by multiple authors.
I guess that if someone told me that they didn't like my short story or thought that it was bad, I would be thinking: "That's understandable, I guess", but that is because I feel like my short story wasn't that good.
I can't imagine myself going to the internet to harass reviewers for not liking my book.
Even though I maybe would be heartbroken if someone said that my book belongs in a trash can or something.
And if I do see some bad reviews, I should instead be thinking about how I can improve the next book that I write.
Reminds me about when someone went to a kpop producer's social media and said something like "You suck and you're a bad producer" and also bashed the way he made songs. But that producer just responded politely with "I was wondering if I should study more music, but thank you for your suggestions."
But well... as I have once said in a thread that kind of was talking about similar stuff, "if you want to improve as an artist, you need to listen to some of the criticism."