Is there a way to bring down the Dark Brotherhood?

Is there a way to bring down the Dark Brotherhood in its own quest-line? If so, how would I start it?

I want to play the game from a completionist's approach trying to finish all the quests, but I don't necessarily want to be a murderer. I am a thief already for the lack of choice concerning the Thieves Guild in Riften, so I hope the game doesn't force me to become a murderer as well.

Yes, you can.

Do the first quest where you kill the head of the orphanage. Get a note from a courier and then go to sleep. You will wake up with the leader of the dark brotherhood in the room who tells you to do something. Kill her instead; it starts you on a quest to eradicate the dark brotherhood entirely.

You can kill the lady in the Abandoned Shack (Astrid) when you wake up. After that you need to go and talk to a town guard who sends you to go kill the remaining dark brotherhood memebers. I think he sends some other guards with you.

This kills off the last remaining Dark Brotherhood people besides the jested, Cicero.