Also here from thisweekmeta--and think, with others, this is a great post although I think (as noted above) that there were some anti/censoring elements within fandom from, the start of it!). I mentioned the anti-pedophile Tolkien fans, and also remember some very heated discourse around some darkfic and grimdark Tolkien stories (a lot of that bubbled up on anonymous hate memes on LJ back in the day).

I could never get into Tumblr though I tried but heard about it from friends active on DW and Tumblr--I wonder if there were some features of how that site worked that facilitated the growth/spread of such behaviors (even before the Tumblr purge).

I really liked your analysis of how certain types of warning posts metatasized--that makes a great deal of sense.