Few things can ruin our internet experience as much as internet trolls. It doesn't matter what you do or say to them, you'll only get madder. And they'll delight in that very fact. Ignoring them preserves your sanity and emotional well-being, but still, there's always that lingering sour aftertaste.
It's not only the trolls. There's flamers too, people who can't seem to respond without an insult and a fiery word. Joining the party are grammar nazis and their related nazis. Why is incivility so prevalent on the Net? Of course, anonymity and the low-barriers to entry possibly encourage such behaviour. But I think part of the issue lies in social norms or what is or is not acceptable; in simple words, the broken windows theory.
The broken windows theory is a criminological theory which suggests that vandalism and littering, basically signs of poor estate upkeep, have a signaling effect that serves to increase rates of crime and anti-social behavior. Well maintained and clean estates therefore have lower crime behavior. The argument is that 'broken windows' signal to people that anti-social behavior is tolerated or not penalized, hence logically criminal behavior is similarly not monitored or policed. In effect, the condition of the environment reflects the acceptable social norms, and affects the behaviors of those in the same environment.
The theory is not difficult to believe. I think we have less hesitation to, for instance, litter if there's rubbish all around us, or to jaywalk if others are already crossing the road before us. We all act based on cues of what's acceptable. Of course, the bad thing is that this tends to be self-reinforcing, after some important threshold has been reached.
My (no doubt tenuous) argument is that this threshold has already been passed. Civility, while still important to most of us, typically disappears in the online arena. A sarcastic remark or failed joke misinterpreted, and tinder sparks go off in the Balkans. Somehow it's become the (unacceptable) norm to respond with an inflammatory reply to a blog post, a caustically cynical jeer, or just a crude, belittling remark.
What's even more terrible is that the Internet generally doesn't go away. It stays there. If it's bad enough, it even spreads and is replicated across several parallel channels. We can probably find the ramblings of the first ancient troll, I think, if we look hard enough.