About two years ago, when Google was in the early stages of the Panda update, it launched another means of helping users get more quality results in front of them. This one, unlike the Panda update, left it more up to the users, giving them more control of their own. That was the domain blocking feature.
The feature has now been killed. Late last year, people were noticing that the feature wasn't working. Now, Google has officially acknowledged its demise.Google says in a message on its Inside Search site (via Search Engine Roundtable):
The Blocked Sites feature is no longer available. To block particular sites from your search results, we recommend the Personal Blocklist Chrome extension from Google. You may also download your existing blocked sites list as a text file.
Google doesn't offer much in the way of explanation as to why they killed the feature. Most likely, it wasn't being used a whole lot, and really, isn't the feature kind of an admission that Google is not getting results right?
At least for those who want to continue blocking sites, Google provides an alternative. That's more that Google Reader users got.