Reznor quoted in the Oct. 16 Rolling Stone article
paying tribute to Johnny Cash:It is precisely that translation [of "Hurt"] that initially unnerved the song's author, Trent Reznor. "My songs have been a vehicle for me to keep sane," he says. "And that song in particular came from a private, personal place. I thought, 'Here's this thing I wrote in my bedroom in a moment of frailty, and now Johnny Cash is singing it.' It seemed incredibly strange and wrong to hear that voice with my song. It kind of freaked me out. But when I saw the video, it took my breath away. It was heartbreaking. My throat had a lump in it, and I had goose bumps, which I have right now thinking about it. At that point, it became inspiring to me. I've been so proud of what they've done with it."
Thanks to Emily.