"Bits" seem to be all anyone is willing to divulge about it.

[ And Matt's tried. Particularly with the shadow of another Matt Murdock hanging over his life, and whatever dark deeds he'd committed. No one wants to talk to him about it. He can't pretend that he doesn't understand why. ]

I have friends who were there for years. Lil was there, for years. And even she doesn't want to talk about it.