I remember working as a private investigator and visiting the United States Patent and Trademark Office way too often as part of my job. And when I read Sarah Bird's post on SEOmoz about an individual named Jason Gambert who is looking to file a trademark for the term SEO, I knew exactly where to go.
The background: an individual named "Mr. Gambert" is trying extremely hard to get his "process" of SEO (or so that's what he claims it is) to be trademarked. He's been rejected but he's been narrowing his scope every so often so that he can persevere and succeed with the trademark filing.
This will hurt the industry heavily if such a thing actually pans out as any SEO could be held accountable (and have to pay) if the trademark goes through.
I encourage anyone interested in pursuing this further to speak with a lawyer (particularly one involved in trademark litigation) to dispute this filing.