If you received the warning message in Webmaster Tools, a penalty has been manually applied to your site. A manual penalty needs to be removed by a living, breathing Googloid.
Originally Posted by firetown
I did have several people come to me after receiving the infamous link warning in Webmaster Tools. All of the site owners were using crappy link building services. None of the site owners had enough time to react before their site rankings dropped dramatically, especially for the keywords that the link builders used in the hypertext links.
Originally Posted by Sami4u
Yeah, it does happen, but there have been so many back-to-back updates this year that is is sometimes hard to tell which one caused a site's ranking to plummet.
Put it this way, it is more common than not for site owners to claim that they lost 50% or more of their Google traffic this year.
Google is running amok and is patting themselves on the back for the great job they are doing, but I haven't seen any web site owners that agree with them.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin