I am seeing one of our sites www.medicarebenefitsdirect.com got hit hard. We just joined Yahoo directory and noticed a huge drop. Also, noticed we are getting a ton of incoming links that we did not do. We were ranked in top 30 even top 10 on many keywords in the medicare supplemental category. Is there a major hole in this algorithm where you could possibly spam links to other sites triggering a SERP filter for targeted keywords. We notice this change recently after getting listed in Yahoo directory.