It probably has something to do with the sentence preceding it about SEO.
"Specifically, the use of our trademarks or names in metatag keywords is trademark infringement, and the use of trademarks or names in page text, metatags, and/or hidden text for purposes of gaining higher rankings from search engines is unfair competition."
This clause itself may be void depending on where you are. You might be liable by law, but what's the point having the clause in the TOS where you can never prove that the infringer ever saw the TOS, let alone accepted it.
"Specifically, the use of our trademarks or names in metatag keywords is trademark infringement, and the use of trademarks or names in page text, metatags, and/or hidden text for purposes of gaining higher rankings from search engines is unfair competition."