kohlrak: Absolutely. Specifically those posts would be the best avenue, because that's actionable, unlike something like "gog has better discounts" or something like that.
GamezRanker: Interesting.
So then, for example: would you say that posts like say Post 4 and 9 in this very thread might count as such?
4's plausible deniability, but 9 removes all doubt. Of course, the user could also be under threat for legal action, as well, and more easily so, but GOG in particular would be a more lucrative target by threatening (if it were property this would be extortion, but a post is not property), demonstrating control, but refusing to remove a falsehood. Thus GOG would be attempting to use it's userbase to attack a competitor and get away with libel. Your average judge would likely side with Zoom on this one.
Disclaimer: I took a law course, but i'm not a lawyer. I just spent some time studying common law, so this is not legal advice, just a reminder of what is available.