Hashtags: Protect your Intellectual Property?

Are hashtags *sometimes* intellectual property? http://www.business.com/legal/are-hashtags-intellectual-property/ For instance our registered trademark "How hard can IT be?" is used everyday online at twitter: https://twitter.com/search?q=%23howhardcanitbe&src=typd There are several questions, but mainly: Do we need to assert some sort of control? According to the article cited above, probably not -- because our Registered Trademark doesn't "Cite a specific…