Reviewers who wish to post a review on former FBI director James Comey’s new book, A Higher Loyalty, may have to find a venue other than Amazon.com.

Only “verified buyers” of the book via Amazon are allowed to post, and some online chatter suggests that low ratings of the book will not make it onto the site. The restrictions apply to print and Kindle book editions.

Those who try to post a review and didn’t buy the book through Amazon receive an error message: “Sorry, we are not able to accept your review of this product.”

So far, the Comey book is getting raves on Amazon, with 4.7 out of 5 stars based on more than 300 reviews.

Amazon has done similar restrictions in the past, notably with Michael Wolff’s Fire and Fury account of the Trump White House, and on Hillary Clinton’s What Happened.

Still, some would-be reviewers were angered by the perceived censorship, posting angry comments on the Amazon Facebook page and other online outlets, noting the lack of negative reviews.