Sockpuppetry is the practise of creating a bunch of fake accounts to, generally, promote your own work through glowing reviews and the like:
Why do some authors think they can get away with sockpuppeting? Sure, you could probably have got away with it five years ago. But the public is so much more tech savvy now. They can see right through bullshit – and discover it, too. IP addresses are easily traceable and, granted you have basic computing knowledge, you can pretty much find out who wrote a review and how many accounts are linked back to the same location.
Margot Huysman looks into various scandals of recent times, noting:
It turns out that Mr Duns has just exposed another offender. Here’s a word of warning, before we continue: if ever you thought the tech scene was bitchy, wait until you get a load of the vicious world of publishing.
It's an interesting read. The comments section continues the controversy, casting doubt on areas of the article and defending/attacking the various players. I think regardless of the details, the core assertion holds true: that it is unethical and unprofessional to create fake accounts to promote yourself or (especially) to attack other authors. If your work can't stand on its own merit, requiring you to artificially pump up its perceived quality or attack other authors, I have one question: wouldn't that time be better spent improving your writing?