"Wondering if some human at Google has reviewed your web site and decided it deserves to be penalized in Google’s search results? Google’s now reporting such cases nearly 100% of the time."
Robin Good: Danny Sullivan reports on Search Engine Land from the Pubcon conference where Matt Cutts said: “We’ve actually started to send messages for pretty much every manual action that we do that will directly impact the ranking of your site.”
“If there’s some manual action taken by the manual web spam team that means your web site is going to rank directly lower in the search results, we’re telling webmasters about pretty much about all of those situations,” he added.
This article reviews the two types of actions that Google applies most of the time: a) manual and b) algorithmic. Google prefers to refer to them as “actions” rather than penalties. Here their key traits and characteristics:
Via Robin Good