A particular breed of political troll has grown up within Newsvine.
The first thing to point out is this is not a casual troll. What we're dealing with is the strategic troll, that is, a person or a group of people who have invested months, or even years developing their personas. These people are not in it for the amusement. Oftentimes they are paid operatives whose tenacity exceeds the grip of a junkyard dog's bite.
These trolls take on a few distinct methods. There is the concern troll, and the tone troll, and the anger troll.
Concern trolls will pretend to support the same causes as you do, but their intention is to undermine your support. For example, whereas killing OBL ought to have solidified democratic support for our military, the troll's goal is to immediately chip away at that support*:
You left wingers are wasting an important opportunity. instead of this petty bickering, now is the time to agitate to leave Afghanistan. Our original purpose going there was to get OBL. we did and now it's time to leave. You should be saying that.
The Tone troll will say "can't we all agree to more civility?" Often this is just a final parting shot after a year of abusing readers, before they get themselves banned, but it's mostly used to push the falsehood that "both sides are equally guilty."
The anger troll is like the concern troll who pretends to agree with his opponent, but the anger troll wants to whip up emotions to incite people to agree with an otherwise unreasonable statement. I.e. "I've had it with Republicans! The next one to propose a tax cut for the wealthy ought to be shot!!"
A troll has two main missions: To waste your time and direct the conversation. Wasting your time is the bigger of the two objectives, because wasting your time is in itself a way to control the conversation.
Most people assume the political troll's intention is to control the narrative, and certainly "flooding the zone" is one of their overall goals. But they can't force their opponents to parrot their propaganda talking points so they must silence their opponents somehow. Since they can't really "silence" their opponents, they do the next best thing. They waste their time.
The most common way to do this is to not link to an authoritative source when saying something supposedly factual, yet controversial. I.e. the troll would say "the Earth's average temperature has only risen 0.1 degrees since 1962." This will invite a slew of people who chime in to refute that claim with the actual data, or to challenge the troll to provide a source. The troll could care less that in the end he will have been shown to be ignorant on climate change - the article was about ending tax subsidies to fossil fuel producers.
The next most common troll tactic is to intentionally misinterpret what you've said, turning "Some S is not P" into "No S is P." For instance, if you say "the most likely people to not pay taxes are rich people," the troll will claim you just said "all rich people don't pay taxes." Good luck trying to clarify your position.
Another troll tactic, which is actually used more than the previous two, is the grammatical mistake / misspelling. These serve a twofold purpose. The first, of course, is to waste your time correcting them. The time you spend pointing out a misspelling is time that you have not spent addressing the topic at hand. The other purpose of the intentional misspelling is that it makes the troll look authentic to his readers. Nothing smacks of liberal elitism than someone who knows how to spell "suffrage." I would love to conduct a study that measures a poorly educated person's level of trust against the number of grammatical mistakes in the opinion they're reading.
All of these methods serve the purpose of topic dilution, whether it's done by flooding the first comment with meaningless replies, or deteriorating the conversation into "gossip mode." It's not enough that Driftwood came, trolled, and was banned - now her minions must talk about her banning.
"CRITICS RARELY CREATE"
Topic dilution also happens on the newsvine front page as the troll network posts articles and seeds which are intended to bump more substantive ones. Articles written to slide others off the front page will come from both sides of the political spectrum. Of course, they will never contribute anything useful for the opposing team, so look for vapid, inane, self-authored rants that reinforce negative stereotypes and are about 10 days past being timely.
The best reply to a troll is a short one that mentions the fallacy in passing and quickly gets back to the topic at hand. Don't be afraid to mock the troll because group laughter destroys their credibility and their influence.
Remember that trolls have no shame. They will play dumb and ignorant, allow you to school them in trivial data, and when they've finally destroyed their own credibility, they will discard that nickname and use one of the alternate accounts they set up six months ago. Therefore, you are never "winning" a debate with a troll, you are only at best spinning your wheels.
Above all, take a step back. Ask yourself "is this person just taking the piss? Is my chain being yanked?" Trolls get the most out of making their readers angry, but a lot of times it isn't as obvious when they're pressing your buttons.
It's a few years old, but we should all keep this comic illustration in mind before we draft a knee-jerk response to that next idiot.
* this is used as an example of what concern trolling would be, however, most accusations of concern trolling are when someone is actually being, well, concerned. It should not be inferred that I am accusing the author of being an actual troll.
UPDATE: The comments have shown me that I'd forgotten the macdaddy number one troll comment of all time. Because the "both sides do it" meme needs an eventual outflow...
"Nothing to see here, move along now."