If you interact with an author in any way online, beware: Amazon might decide that you’re “friends” and ban you from leaving a review of their latest book.

The online retailer appears to have tightened up its review policy to weed out people boosting their mates’ books with glowing notices, but whatever algorithms they’re using to work this out seem also to be catching anyone who engages with their favourite writers on social media.

The policy has prompted allegations of “Big Brother” activity and sparked a petition calling on Amazon to reverse the decision, organised by US romance author Jas Ward, which is heading towards 11,000 signatures as of Thursday morning. Ward has penned an open letter to Amazon on the change.org petition site, writing:

In the world where both indie and traditional authors are using all tools available to try to get their latest books out to the reader, it’s essential for the authors and their associates to use social media, ie Twitter, Facebook, Instagram, etc. With that being said, a reader is therefore going to have cookies and data when they see that interaction and very likely would have LIKED and/or followed the author’s pages, profiles and other avenues being a fan of the author’s work. They are fans after all – they want to know what an author does and their current news and title releases. Your current process of removing reviews that a reader has created to show their honest and sincere opinion on a book is not fair and cripples the review process more than assists.”

The petition was sparked by a blogpost by indie author and book blogger Imy Santiago, in which she said: “A couple of weeks ago I read the third instalment of a series I really loved. Like any reader, as soon as I finished reading, I wrote my review. When I tried posting it on Amazon I received a rather concerning email.”

The email told Santiago that she was “not eligible to review this product”, which she challenged with Amazon’s customer services team, who she says told her: “We cannot post your customer review to the Amazon website because your account activity indicates that you know the author.”

Santiago says she has only interacted with the author in question online and doesn’t know them personally, and writes: “It is censorship at its finest. I have interacted with a couple hundred authors over the past year; from events to signings, authors and writers rub elbows during networking sessions. This does NOT mean I know you personally.” She adds that Amazon has “spat in the face of those authors and writers whose work deserve praise and recognition”.

On both its .com and .co.uk sites, Amazon has the same customer review guidelines, which include the warning: “Family members or close friends of the person, group, or company selling on Amazon may not write customer reviews for those particular items.”

But how does Amazon work out their definition of “friends”? It looks likely to remain a closely-guarded secret. In its email to Santiago, the retail giant wrote: “Due to the proprietary nature of our business, we do not provide detailed information on how we determine that accounts are related.” - which prompted Santiago to brand their actions worthy of “Big Brother” in her post.