Back in March 2013, Google penalized an underground link network named SAPE. It seems like Google may have gone after this same link network yesterday.
We are seeing reports in various “black hat” SEO forums that their website rankings in Google have dramatically fallen overnight. It seems, based on the reports I am reading, that the commonality between all the websites is that they were all using a link network named SAPE. SAPE was previously targeted by Google in March 2013, but they revamped their system and quickly became a network many link schemers used.
It is hard to say if Google did actually go after a specific link network. Google typically does not comment about these situations. We have emailed Google for a comment.
If I had to guess, I’d think this is related to the harsher penalties Google promised to issue to webmasters who have repeated violations. But none of these webmasters have confirmed receiving a manual action in their Google Search Consoles yet. This could also be related to the hacked sites algorithm, or maybe Google is about to release a new Penguin update. We know it is expected pretty soon.