Recent example from history:
Hearing about communism in the soviet union, from people who lived in the soviet union.
vs
Hearing about communism in the soviet union from Joe McCarthy, and his cronies. (Or from Stalin's PR machine, either one is just as bad.)
This is not a flattering comparison. In your example, what possible motive could communists from the Soviet Union talking about communism have for talking one way or the other?
It is important to keep in mind that there does not need to be an obviously malign agenda, like with the prior example. People can truely mean well with thier interjections-- The problem persists though; They are raising their own (imagined) perception of the problem, rather than using their resources to hand the mic over to people that actually experience the problem. When that happens, they drown out the signal, and make only noise.
It is most amusing reading of blind and deaf Victorians complaining about those trying to help them making their pains most pronounced.
Another great example of both these phenomena would be the two-faced sanctimonious money-grubbing crypto-nazis who run Autism Speaks
There is a story here that demands explaining
I'm not talking about gossip magazines, I'm talking about the TV news, most of which is either celebrity gossip (including some news which at first glance appears to be legitimately politically informative; "OMG Hillary Clinton used a poor choice of words to describe the Bengazi attack!?") or else sometimes even just regular gossip (Human interest pieces. The Jonbenet Ramsey murder. etc.)
You'll have to be more specific which TV news channels you're talking about. American? Which is erm... Not the highest quality around.
I'd consider myself progressive, but I don't particularly like people who think delusionally and think everyone else should join them in their delusional thinking, whether they're "progressive" or "conservative." For example, if you think that disagreeing with someone is equivalent to personally attacking them. Or anyone who ignores facts in order to believe a more convenient story for their worldview. For example, the forensic evidence proves that Michael Brown was charging when he was shot and killed - but that doesn't accord with the narrative so it's ignored for unreliable witness testimony. Of course, for many people it's entirely believable that the police would fake forensic evidence to exonerate an officer - practically every time there's a shooting with a video released later it seems like the initial report by the police officers involved is completely untrue.
The George Zimmerman case was even more blatant in this regard, where a hispanic man shoots a black man who was sitting on top of him smashing his head into the pavement because he was angry about losing a fight and wanted to beat someone else up instead to get his pride back, Murrican media actually edited his police phone call to make it sound like he was a white supremacist who chased down an innocent black kid and gunned him down in cold blood - even editing out his head wounds in order to keep the reaceb8 real. The saddest thing was, despite the whole debacle occupying Murrican media for months and even Obama picking sides (conveniently detracting from the whole mass surveillance thing) no one watched the trial themself :/
It was quite disheartening to see a non-partisan issue become partisan, but it was especially intriguing to see that in spite of progressives and republicans facing off, both had either picked the right or wrong side both for the wrong reasons, neither having actually reviewed the evidence; only what had been presented to them by the scummy media.
On the original subject, it's certainly possible to change your opinion in an internet discussion. Not getting into giant flamewars helps. Keeping an open mind helps. Recognizing when someone is right when they tell you that you're wrong helps (and controlling the urge to try to justify or make excuses for when you post something dumb and someone calls you on it, because doing that just tends to lead to flamewars).
Possible, better done with anonymity - no need to save face.
Yes, "echo chamber" is definitely preferable, as it doesn't falsely differentiate Social Justice Warrior phenomena from it's counterparts on the right (such as fundamentalist churches, capitalist/Randist-objectivist/Mammonist forums, the NRA, goldbugs, and Stormfront)
What part of the differentiation is "false"? What does someone demanding you check your privilege have in common with people telling you BUY GOLD BUY GOLD? Why would a Randian in the free market of ideas not warrant differentiation from the safe space of an SJW? Why would a fundamentalist group whose streams are prone to internet raids not warrant differentiation from SJWs that organize their social justice on those same media? Mammonists, I must say I have never seen them before. Stormfront and SJWs have the most similarity of them all, but they are not the same any more than communists and nazis are the same despite their great similarities (not surprising given which side of the oxbow they align themselves with). Take 5 minutes on
Stormfront or SJW where you have to guess whether what was said was said by a neo-nazi or SJW after all the group labels have been obfuscated. Those 5 minutes are pretty much all you need to recognize the patterns in writing style, rhetoric and lexis which marks whether one's a neo-nazi or SJW. They both want to exterminate their outgroups but that's where the similarities end. These differences extend all the way through organizational structure (decentralized vs network) to tactics (protocols vs rules). Even the most similar groups only appear similarly in obnoxiousness; and certainly not in influence. This is the equivalent of people talking about jihadist terrorism and then some bloke keeps chanting "BREIVIK" - dilution of discussion achieved
Circlejerk, echo chamber, containment, wankfest, gulag, fee fees - hugbox; the differentiations are based and make people not interested in intellectual discussion infuriated. Why avoid them to appease fundamentalists?