Noted recently some unusual domain names showing up for certain searches and did a little investigative work. Seems recently Google has turned off whatever filter they had in place for recently expired domains, as I have now seen a domain that had fantastic rankings in the past for specific types of tutorials in web design had dropped at the end of Sept. The person that picked it up on the drop immediately placed cloaked "keyword rich" text pages up for googlebot redirecting to other pages he used in an entirely different industry. Cache dates for the new pages show two days after the domain was snapped, and one day later, has top 10 spots for some of the best money phrases out there in one industry.
I guess its time to start watching the domain drops again