Following the recent Panda update a few weeks ago, Panda 3.4 - and while Google is preparing for the April 2012 search update "Over SEO Penalty" -- over the past few hours search forums like Webmaster World and Google's search discussion areas are a buzzed with a recent drops in search ranking.
In the WebmasterWorld thread one user said:
"Our niche has been heavy shaked up. Most of the upcoming ecom sites are low quality - > I think it has somthing to do with the "overoptimzed" and "level" efforts, cause this shops only have little ranges and will not hit the SEO overoptimized barrier."
As some speculates if this was the release of what's been dubbed an "over-optimization penalty", but it turn out that this is not the "over optimization" penalty. Matt Cutts in a Google+ post releates it to a "classifier for parked domains" which went haywire. Google fixed the issue, Cutts said:
"I saw a recent post where several sites were asking about their search rankings. The short explanation is that it turns out that our classifier for parked domains was reading from a couple files which mistakenly were empty. As a result, we classified some sites as parked when they weren't.
I apologize for this; it looks like the issue is fixed now, and we'll look into how to prevent this from happening again."
Also, recently on April 16, Google sent out about 20,000 warnings to webmasters that have had their sites compromised and may have no idea about it. Cutts responding to issue tweeted they sent out these notifications of "your site might be hacked" for sites suffering from "weird redirects."
Is your site doing weird redirects? We just sent a "your site might be hacked" msg to 20K sites, e.g. goo.gl/S6Ptk-- Matt Cutts (@mattcutts) April 16, 2012