Do you know what sock puppets are? I thought I did because we made some with my Brownies while working on the Puppets, Dolls & Plays Try-It. Apparently it means something else that authors need to be aware of when seeking book reviews. Urban Dictionary defines sock puppet
as "an account made on an Internet message board, by a person who already
has an account, for the purpose of posting more-or-less anonymously." As it applies to books, these would be people who post reviews writing under false names and/or false pretenses. There are services that pay people to write favorable book reviews with or without the benefit of having read the book. And authors are the ones who are paying for these services.
As someone who has published several books, I know how hard it is to get someone to write a review on your book. I can see that it might be tempting to pay a service to solicit reviews. It is hard to garner attention for a new book, and certainly having positive reviews can help especially if you are selling on Amazon. But paying for reviews certainly seems disingenuous to your readers. There are many legitimate people online who will review books, including a multitude of book bloggers. As with all other things in the self-publishing world, there are no shortcuts.