Comcast DNS fail

So... according to Twitter and news.google, Comcast is down in IL, IN, MN, MI. Which is a lot of areas to be down in. DNS issue. Fix it by following instructions here. https://code.google.com/speed/public-dns/docs/using.html#setup

I would be unsurprised if someone hacked Comcast in return for the Netflix thing. It's not like Comcast is universally loved. I'm watching how this plays out with some interest. Mostly by keeping an eye on http://twitter.com/#!/comcastcares

If it was an accident, how did this accident come about?