Ponies, by Kij Johnson

And one more, for today, because after I read this I just had to.  Ponies is a very trenchant commentary on primary school girls.  Hits pretty darn close to home for me.  Really you should read it rather than have me spoil it for you.  I'll just say that little boys that beat the crap out of one another are much less cruel.  We think we can protect our daughters from these sorts, but we cannot, in part because our daughters turn out to be the perps as well.  The unicorn metaphor is cutting way too close to the bone.  This will get strong consideration for a Nebula, but would be somewhat surprised if it won.  Yeek.