Here is a picture with the “block all domain.com ads”:
What is interesting is that this works for both those who are signed in and signed out of a Google account.
When Google launched Search Plus Your World, the ability to block sites with this feature went away and still does not work. The interesting part is that if you are logged in, you can block AdWords results but not normal web results.
Hat tip to Andrew Girdwood for spotting this over the weekend.