Because calling their face computer "Google Glass" is too clunky for the Mountain View hivemind, the company is trying to trademark the word "Glass". Their justification for such a transparent power play? The media talks about Glass so much, they might as well own it.
The U.S. Patent and Trademark Office allowed the company to trademark the full term "Google Glass," but objected to the shorter version because it was too close to other existing computer software and was simply a descriptive word for the company's tech toy du jour. Google disputed those objections in typical Google fashion: by throwing mountains of search results at the patent examiner. The Wall Street Journal reports:
Trademark attorneys for Google, Anne Peck and Katie Krajeck from Cooley LLP, wrote back to the trademark office examiner two weeks ago with a 1,928-page letter in defense of the application. (About 1,900 pages of the letter are just clips of articles about Google Glass.)
The attorneys disputed that Google’s proposed trademark would confuse consumers, especially given how much media and policy attention the Glass device has received in the last couple of years.
Anyhow, Google doesn't need to own the word "Glass," really. They would just like to be able to sue anybody who harms their spectacles' good name.