One of Google's systems currently in place has been used for three years and is just now receiving its patent. This article gives a brief explanation of the patent that was filed by Matt Cutts and Fritz Schneider on August 25, 2009. A link is also included to Bill Slawski's blog that explains the abstract quoted here in more detail.
Even though Cutts filed for a patent three years ago, he has just now been awarded a patent for his work. Having the patent means that no one else can now come and change Cutts' work and then patent and sell it themselves.
The system that Cutts and Schneider worked on was designed to find hidden links on websites. As website owners began learning that relevant links were important to search engines, some of them began working on ways to embed links on their page without giving the reader the option of following the link. This could have been done by using white text on a white background or using text that’s too small to be picked up by Google.
Thanks to Cutts, the playing field remains level for all site owners, and unscrupulous ones who try to hide links can be dinged by Google.
