Wank among fans...about... well, not wanking.
This isn't exactly fandom, but I found it freaking hilarious in how pissed off people will get about something so stupid. It's from the off-topic area of an anime-related board.

(Utterly NSFW, all text though)

Mr. 'Dr. Drew says they don't stretch' vs. 'Now what happens if every single time you masturbate, you have to stick your whole fucking fist in there. IT'S GOING TO STRETCH OUT, YOU FUCKING MORON.'

...the latter of which may be my favorite quote from the whole thing.

The original post is a parody of an earlier post about whether size really matters. It quickly derails into a debate among guys who apparently know little about female anatomy but are REALLY eager to shout each other down about what they do think they know. And the less they know, the more angry they get.

The main players are Freako and Jace "I've watched girls fist each other" Tsunami.

And probably the most on-target of all:
"considering like 0.2% of the active members here have even seen a 3D pussy.. "

It derails after page 3, but that's where the highlights are anyway.

Oy. Okay, it probably is stupid, but it had me cackling like a madman. Hooray for anime-fan stereotypes.