A significant number of subscribers got spammed by this list today. Routine maintenance of the development server at Duke triggered a mistaken torrent of hundreds of old posts. The biggest problem was that there was a partial subscriber list as part of the development instance of the blog. That list has been removed, so this particular problem should never happen again. There was no hacking involved, and subscriber e-mails did not get harvested or released to anyone.
I am very sorry this happened. I certainly understand if folks want to unsubscribe from the list, but emphasize again that the production version of the blog did not cause this and was not compromised. The list of subscribers that was inadvertently associated with the development instance is no more.