There appears to have been a Penguin data update either yesterday or early today. What makes me so sure? Well, I set up a little Penguin trap. I built a one-page site, tuned for a nonsense term, and built about a dozen links to that page with the nonsense term as anchor text. Then, I waited until it ranked #1 for that term…that took just a couple of days. The pages that linked TO that page all rank for that term, as well. So, once my nonsense site ranked #1 for that term, I disavowed all links. And waited. Till today. BOOM. After not moving a single spot for the past month, it suddenly dropped 9 places.