Concern troll

Imagine being on fire, running up to a firefighter screaming for help, and they hook their hands in their pockets and say, "Actually, before we start, I think you should say you're violently oxidizing. Not all oxidization is bad. I mean, some of my cells are performing oxidation right now, and I think it would be better if we ...

A concern troll is someone who disingenuously visits sites of an opposing ideology to disrupt conversation by offering unwanted advice on how to solve problems which do not really exist. Topics of "concern" usually involve tactical use of rhetoric, site rules, or with more philosophical consistency. The concern troll's posts are almost exclusively intended to derail the normal functions of their targeted website.

Alternatively, a concern troll is someone who enters a discussion with a pre-formed opinion contrary to the majority opinion, but pretends to conform in order to subtly sow dissent and doubt without being called on it. Such attempts often begin with the troll raising "concerns" about the topic of the discussion, hence the name.

While this is a common internet phenomenon, the term is open to misuse. More paranoid circles (and echo chambers) may accuse someone of being a concern troll for the simple crime of not blindly agreeing with all of the group's dogma.

Typical formulation and tactic
A typical formulation might involve the troll's invocation of a site's espoused ideals alongside a perceived example of hypocrisy (such as contrasting "we value free speech" with the banning of a "dissenter"), and with a call for some relevant reform by the troll. This reform will frequently be burdensome or silly — the concern troll's message is: "I have some concerns about your methods. If you did these things to make your message less effective, it would be more effective."

One common tactic of concern trolls is the "a plague on both your houses" approach, where the concern troll tries to convince people that both sides of the ideological divide are just as bad as each other, and so no one can think themselves "correct" but must engage in endless hedging and caveats. This preys on a willingness to debate critics and allow dissent; everyone wastes time discussing the matter and bending over backwards, so as not to appear intolerant of disagreement, all to the great amusement of the troll.

If the troll provokes a negative response, it can be used to their advantage; the troll can later claim that their victims were unreasonable and closed-minded, doing damage to their reputation. The victims might be so on the defensive against further concern trolling that they end up disregarding and mistreating outsiders with genuine concerns. This makes it similar to sealioning.

Sometimes outsiders will come by and make concern troll-like statements sincerely. Some are sincere but stupid. Some may be insightful, and justified iconoclasts, merely making valid observations unwelcome to the dominant ideology or culture of the forum (the Cassandra syndrome ). Often, of course, the person is misguided, wrong, and not intending to troll. However, an unsolicited tone argument is, in practical terms, not really any different.

Popularity and history
The term's popularity originated on Daily Kos,  though the term likely predates their usage.

Perhaps one of the best descriptions of the concern troll even before any proper nomenclature was by Martin Luther King in, "Letter from a Birmingham Jail."

The tone argument was mentioned before, but it's pretty fitting that he covered both concern trolls and tone arguments in the same breath.

Caveat lector
The danger, of course, is that not everyone with a concern is a concern troll — and not every concern is unreasonable. In environments of genuine groupthink, applying the concern troll label may serve as a means of enforcing conformity and punishing (or silencing) dissent. And even without actual groupthink in play, many Internet posters find dismissing an argument much quicker and easier than evaluating it. In addition, the term "concern troll" focuses not on what the person is actually saying, but on some alleged agenda.

Thus, if misused, it is the perfect refuge for someone who has no counter to the actual argument: simply ignore the points made, allege some other position, and then accuse the other person of lying if they deny that that is what they're really saying. It's a combination of straw man and argumentum ad hominem: make up something to attack, and ignore their actual points on the basis that since the points were made by someone acting in bad faith, they need not be addressed.