Google's John Mueller said in the Google hangout this week that there is no need to disavow sitewide or blogroll links. He said this at the 2:12 mark of the hangout that if the links are natural and organic, there is no need to disavow the sitewide or blogroll links.
Here is the transcript:
In general, if these are normal links -- organic links -- that are happening that are pointing at your content, then I would just let them be. That's the way the internet works. People link to your content. If your students have blogs and they think, oh, this is actually a teacher that knows what he's talking about, then that's a good link. That's not something you need to disavow just because maybe it's a sitewide link or in the blogroll.
Here is the embed:
The deal is, with the real time granular Penguin out, Google will just devalue them, not demote them. They did this actually in 2006! We covered how Google at that point didn't count the Washington Post blogroll because they abused it back then.
So just because they are there and Google says there is no reason to disavow them, doesn't mean they count well. I am confident Google applies a link label of blogroll or sitewide to those links.
Forum discussion at Google+.
