Algorithm change went into effect earlier this week.
Google web spam czar Matt Cutts blogged today about a recent algorithm change to Google’s rankings.
The algorithm change is a follow up to Cutt’s post a week ago about addressing low level “content farms”.
An algorithm change designed to address these concerns launched earlier this week. It specifically addresses “sites that copy others’ content and sites with low levels of original content”.
I suspect this primarily refers to site scrappers, sploggers, etc. instead of sites like Demand Media’s eHow, which was at the center of attention after Cutt’s first post. A number of commentors have asked this but have not received a response.