Winterfox is a Thai troll who has single-handedly destroyed multiple communities by attacking members. I mention her nationality because she is especially fond of racial one-upmanship. She loves to say, "Are you white?" If you're not white, but not "Asian-Asian" as she so charmingly puts it, she will attack you for being inauthentic.
50 Books POC is an LJ comm devoted to reviewing books by authors of color/nonwhite authors. No need for the reviews to be positive, but it was a civil comm without a wanky history. Rachelmanija, who is white, was a frequent reviewer there.
Enter Winterfox. She hates several female authors of color, most notably Cindy Pon and Nora Jemisin, and began to haunt 50 Books POC to verbally abuse any authors who posted positive or insufficiently negative reviews of their work. And by abuse, I mean stuff like, "Your liking for this pile of verbal diarrhea proves what morons fantasy fans are." Posting began to slowly but surely fall off at the comm.
Winterfox then posted a review of a Cindy Pon book which not only ripped into the book, but called the author a "stupid fuck" and a homophobe.
Rachelmanija commented to say that she hadn't read the book, but that personal insults were inappropriate on the comm. Winterfox responded by personally insulting her. Rachelmanija repeated that personal insults were inappropriate on the comm, and added (remember these words) "This isn't 4-chan."
The comm exploded. Spiralsheep popped up to say that "This isn't 4-chan" was a racist insult. Winterfox concurred. Posters seemed confused as to how it was racist, and Winterfox said that it was because 4-chan was the home of Nazis and pedophiles. Winterfox and Spiralsheep demanded an apology from Rachelmanija.
Rachelmanija apologized, saying, possibly sarcastically, that she did not believe that Winterfox was either a Nazi or a pediphile. She then left the comm. Spiralsheep accused Rachelmanija of asking her friends to racially harass Spiralsheep. Rachelmanija returned briefly to say that she didn't know anything about that, then left again. (This was Rachelmanija's last appearance on the comm.) No racist messages were ever produced.
The comm continued to explode, as members were now arguing over whether or not it was okay to insult one another or authors so long as the insults weren't racist. Winterfox accused Hesychasm, a Cambodian-Chinese woman, of crying "white women's tears," then hastily deleted the comment. Spiralsheep warned Rachelmanija that she had screencapped all her comments lest Rachelmanija delete anything. Winterfox called Rachelmanija a rape apologist because Rachelmanija's earlier review of a different Cindy Pon novel failed to warn that it contained sexual assault.
Posting to the comm fell way off, and some time later, Winterfox deleted her LJ. Months later, she reappeared in the comments to DeepaD's DW during YesGayYA to call Rachelmanija and her co-writer Sherwood Smith "yaoi-loving weeaboos" and to claim that harassment from ffa had driven her off LJ.
...
As I recall, the mod was really waffly on the topic of whether it was okay to call other comm members "morons," demand their racial credentials (and question them at length to see if they were good enough credentials), or say of a PoC author that she was a stupid fuck who couldn't do anything right. My interpretation is that the mod did not actually think those things were okay but was too scared of winterfox to do anything about it.
I also remember that pretty much the only thing that seemed to get any traction in the debate was oppression olympics: it didn't do any good to say, "I'd prefer not to be called a useless fuck by comm members, thanks," but you could maybe get some consideration if you said, "Being called a useless fuck triggers me because it ties into ableism with regards to mental illness" or something. It was almost parodic, the way opinions had to be couched.