Don't feed the trolls
Back in a previous life when I joined DU, the term "troll" probably didn't even exist. (Except for those ogre type creatures that lived under bridges.)
I remember that when i posted something controversial, there were those who didn't just disagree, but went into full attack mode. And that, of course, pissed me off, and I'd respond in kind.
It took me a year or two to decide to never respond to anyone I considered to be an asshole (which was, of course, a subjective opinion on my part). Nonetheless, I found that responding just led to a "Fuck you!"/"Fuck me? Fuck you!" exchange that ate up most of a thread and killed the issue under discussion.
Over time, I learned that not responding helped to keep the thread on track. Today, I see far too many threads that go off on a tangent because of responses to a troll who may have intentionally been trying to destroy a thread.
It's difficult to ignore responses to OPs that are outright attacks, or, more likely, troll bait to get you into an argument and destroy the topic of the original post.
Over 10 years ago, I made it a personal rule to never respond to those who were either intentionally seeking to disrupt a conversation, or those who were making outright fools of themselves.
Today, many threads can be shortened and kept on point by one simple self-imposed rule. Don't feed the trolls.
= new reply since forum marked as read
They are usually the ones who have countless replies on almost every flaming thread (again, again and again... many for years).
DU is a far better place to visit without all their drama. 
I recently learned about this issue the hard way. You can't reason with some people who are just looking for a fight. If the criticism isn't constructive just let it roll off your back like water off a duck.
