In fact, Google's Matt Cutts insinuated that Experts Exchange was one of the most blocked sites in the Google Blocked Sites tool and web search feature.
In a Hacker News post on how much traffic the site lost due to Panda, Google's Matt Cutts replied:
One of the signals that we've said that we use in the Panda algorithm that launched in April is how many users blocked a particular site.
To me, a response like that in response to Experts Exchange losing their traffic due to Panda, means that the site was one of the most blocked sites by Google searchers. Of course, I can be wrong and looking too deeply into this.
Forum discussion at Hacker News.