This doesn't seem like an impossible problem to solve for at least 80% of cases. I'm sure there's a long tail of review bombing, but in any given week, how many

This doesn't seem like an impossible problem to solve for at least 80% of cases. I'm sure there's a long tail of review bombing, but in any given week, how many different titles are being brigaded? They say there are 300 volunteer "librarians" who moderate reviews: a relatively safe plan would be to get another couple dozen of them, give them a dashboard to show clusters of unusual review activity, and see how many wildfires they can put out just by throttling the number of reviews, or temporarily halting reviews for a book.