The rumors floating around the SEO industry right now is that Google has crushed yet another link network. SAPE links, a link network I honestly never heard of, was the target this time. Any of those using SAPE links were supposedly penalized and downgraded in their rankings over the past 24 hours or so.
We have dozens of threads about downgrades of Google rankings but the black hat SEO forums all seem to point at SAPE Links as the cause.
Black Hat World and Black Hat Group both seem convinced the reason for the downgrade in rankings in Google yesterday was due to having links from SAPE links.
However, others are not sure if it is specific to SAPE or some other link network.
There is clearly something going on, it doesn't seem to be an algorithmic update but it does seem to be a targeted penalty attacking specific link networks and the sites/webmasters that use them.
Here is a list of threads that are complaining about ranking declines at Google Webmaster Help.
A tweet from about a month ago from Google's Matt Cutts kind of supports this. SAPE Links is a Russian link network:
@dannysullivan @seocom just another day at the office for me. :) Okay, gotta look at some really naughty Russian link selling software now.
— Matt Cutts (@mattcutts) February 13, 2013
Forum discussion at Google Webmaster Help, Black Hat World, Black Hat Group and WebmasterWorld.