Ralph_Slate - 4:29 pm on Aug 10, 2012 (gmt 0)
@Jez123 - no, the spammers generally aren't altering the links (though some are stripping out the nofollows). I am suggesting that maybe the Penguin algorithm is looking at things differently than the main algorithm and ignoring the nofollow attribute when computing a penalty.
Google wants to actually punish spam sites with Penguin, right? They've pretty much said that. They could have implemented an algorithm that simply ignored backlinks from spam sites, but they went further - they hit sites being linked to by spam with a penalty. They were hunting spam, not just ignoring it.
So isn't it within the realm of possibility that they also said "for our hunting algorithm, we're going to zero in on the content spammers - even if the links have been nofollowed, we're going to look at a site's total backlink profile, and if 50% of their backlinks are nofollowed, that's a signal that something is up".
Well, 60% of my backlinks are nofollowed because of Wikipedia and the Wiki cloners (plus the fact that my site is often linked to by people commenting in blogs and online forums - sites that often have "nofollow" turned on automatically).
Maybe Google didn't think about the Wiki spammers. Maybe it's penalizing us anyway. 1 Wiki link seems to generate 100+ spam links. Although being tied to Wikipedia *should* be a good thing, maybe it is a curse?