I tend to down mod rude and aggressive people on here and I also up mod people who I think have been down modded unfairly.
I am not sure if I am alone with my way of thinking.
That's not a troll behavior ("troll" comes from the fishing term), and it's much less common here than on reddit or digg or (god help you) dailykos, where intelligent but unfashionable opinions get sunk hard.
There are only a few fashionable subjects around here (the importance of lisp, for example), whereas on other sites almost every question has a boilerplate answer, against which all opposition is "trolling". At any rate, no amount of actual "trolling" is as bad as groupthink. I'd rather a whole parliament of disagreeable colicky horseradish farmers than one unipartisan politburo.
ADDENDUM: Just thought I'd tack this on. Near the top of digg right now is this:
http://digg.com/business_finance/What_1_Million_Buys_In_Home...
That's sort of an interesting subject, but look at the comments. At the top with 9 diggs:
I dugg the story, but I refuse to click on anything with Forbes magazine. They force a full-screen ad (that you can skip) but in my efforts to help stop obnoxious advertising, I boycott Forbes.
Okay, there you have a 15-year-old combining 1) his irrational dislike of full-page ads (perhaps he thinks Forbes survives on government grants), with 2) his irrational proclivity to upmod things without looking at them, with 3) his belief that Forbes cares whether a 15-year-old looks at its slideshows. This sort of sad lameness is actually what kills online discussions, not "trolling".