Have you ever had an author send you an ARC for read-and-review, only to discover that much in it has been pilfered from your own published work? That you have helped said author previously to promote their first novel and they haven't even acknowledged that they have read your work, much less rated it. Then they have the audacity to send you a sequel presumably so you write a positive review that will help them promote it. As you read said sequel it's really familiar and you find yourself saying, 'I know why it's familiar, I wrote about that in my book... and that...and that...that too!'
I am not talking coincidental commonalities here, I'm talking bold-faced pilfering of characterisation and plot. You have? Well, me too.
Should you be flattered?
If the book is done well then maybe you can take your hat off to the author. You might think, that was sneaky, but at least it's good. (I would in any case.) But what if it's the sequel from hell? What if you wrote a 5 star review for the first one and the sequel reads not so much like a sequel to the first one but poorly executed fan fiction of your work. (How is such regression even possible?)
It would appear that while I saw this author as a peer, said author saw me as a competitor. Perhaps I am naive (clearly I am, but for me writing is not a business but a labour of love). I have had wonderful feedback about my books but I don't apply ratings to my own work and self-promotion is a chore. I believe I have potential as a writer but I strive for perfection. It's a surprise to discover someone would want to pilfer my work. Warped as it may be, it is a massive compliment.
If I am right and it is the sequel from hell (in this case, more likely to alienate it's target readers than not), and assuming said author ignored my feedback and left the reader-alienating gaffes in (yes, foolishly I did try to help fix it), this is bound to be reflected in the reviews. Time will tell.
C'est la vie!
I won't be put off by this experience. I will continue to support my peers (although not that particular one).