But it's a fine line, and in the end you have to decide whether you're ok under free speech with someone taking the "Hitler was a net positive" position [on a Jewish dating site] or if that's a form of harassment.
Wait, what? "Science confirms"? Mainstream psychology isn't scientific, and this is social psychology, which doesn't even make good fiction.
As usual in psychology articles, even the title contradicts itself -- science doesn't confirm (prove) anything, it can only support theories with evidence, while disproving a few theories along the way.
More here: http://arachnoid.com/building_science
I seriously doubt that extroverts waste their time trolling others online. They probably have much better things to do in real life.