Aaron Wall posted an example of a large brand manipulating Google through an old spam technique. In short, they were buying expired domains to piggy back off of the link popularity and anchor text of those old domains.
Aaron wall said, "buying expired domain names for links is something Matt Cutts loathes." What I find most interesting is the video he posted after (spam doesn't always interest me all that much these days).
This video was done by Matt Cutts of Google about two years ago. He talked about the first time he found search web spam.
Forum discussion at Sphinn.