But, let me start off with a few definitions, at least from my perspective.
I'm dealing solely with online financial communities. I'm not getting into the other communities.
Basher - someone who posts negative material all the time and often twists things terrible. they generally focus on one company for months refuting every single positive statement made about the company. Why they do this, I don't know. Is it compensations? Is it revenge against the company, ex-employer? Is it just folks hounding members no matter what stock they are in? We'll go into more details later. Right now, I'm just setting up the definition. Basically, a person who is negative 100% of the time and twists things up.