In the Gold Irritant thread, I admit I didn't know the background of the "basher" on the other site, but another participant explained the interesting history to me...thanks!
I do have experience with a similar situation in another online arena, and it all sounds familiar. I am not terribly worried about such posters, because they tend to create suspicion by being irrational: always negative, inaccurate info, ... So if we all do our due diligence, their lack of credibility will likely be apparent.