Pony Wars
Of all the things to break 4chan, it was My Little Pony. At least, that's what it seems like. I rarely frequent the place, but near as I can tell, something like this went down*:

*I obviously only have one source, so if there's another side of the story out there, let me know and I'll link it.

1. /co/ discovers the new (and awesome) show, My Little Pony: Friendship is Magic. The dark horse of The Hub's lineup, it's become quite popular since it's debut.
2. A significant number of the users on /co/ like the show, and threads start popping up everywhere. Seems like it should be fine, since /co/ is for comics and cartoons, right? Ponies of a different color should fit right in!
3. /b/ discovers Pony. Pony threads start popping up all over /b/. You know, that place where gore, bizarre fetishes, and pretty much anything except for Child Porn and Scientology lives in peace?
4. Pony threads reach 6,000 posts in one day.
5. 4chan's reaction is to put all Pony threads out to pasture.

Reaction comics are made. General consensus is that they shut the barn door too late to do any good.

Eventually a "peace treaty" is "negotiated"...if by "peace treaty" you mean a comparatively restrictive set of rules that ONLY apply to pony posts, and by "negotiated" you mean, "follow these or NO PONIES EVER." Does this mean the fandom will have to change horses midstream?

But already dedicated Pony image boards have been created. Polls are created because no one wants to back the wrong horse.

Breaking news can be found under the /co/ news tag on the blog Equestria Daily, which keeps up with the happenings in bronyland on /co/.