Matt Cutts points to a post by Rhea Drysdale that explains her fight against Jason Gambert's SEO trademark application. On April 24, 2008, Drysdale filed a notice of opposition to Gambert's SEO trademark application. On March 11, 2010, she won.
Cutts explains that Drysdale earned the sort of industry credibility you just can't buy. Drysdale says it took two years, $17,004.33 and an untold amount of frustration and self-doubt to get through this.