Whitey - 1:42 am on Mar 22, 2013 (gmt 0)
Matt Cutts: Here's the official statement from Google: "We're sorry about the inconvenience this morning to people trying to search for Digg. In the process of removing a spammy submitted link on Digg.com, we inadvertently applied the webspam action to the whole site. We're correcting this, and the fix should be deployed shortly."
From talking to the relevant engineer, I think digg.com should be fully back in our results within 15 minutes or so. After that, we'll be looking into what protections or process improvements would make this less likely to happen in the future.
Added: I believe Digg is fully back now.
A fuller transcript from Google. Lots of traffic involved with Digg, so probably fair play. But it does demonstrate what can go missing lower down the food chain.