A Position 6 Penalty?
It could be said pretty fairly that webmasters and SEOers, if dropped a rank or two, automatically assume they’ve been penalized. A recent development, involving the "position 6" penalty, proved to be a reality.
It’s not clear why it was a reality, other than a Google glitch.
Webmasters reported worries about sites that historically had ranked in the top two results for certain keywords had dropped to the sixth position. Dropping to below the top five, or below the fold (below where a person may have to scroll), could mean sudden death in the exposure game.
Though it sounded kind of silly that Google would invoke a four or five-place penalty (for what, a broken link and saying something mean about Sergey maybe?), the number of webmasters reporting the problem added a bit of an urban myth weight to it.
Search Engine Roundtable is reporting that Matt Cutts confirmed a glitch with Google, and that the database is in the process of resetting everything to normal.
There wasn’t much explanation other than that. Guess even Google sometimes makes mistakes.