P designs and manufacturers traction devices. D is a competitor of P and manufactures the same types of devices. D used two of P's registered trademarks on its website within meta tags. D's website never displayed P's trademarked but by including the terms within its meta tags D was able to influence Internet search engines. If a computer user entered the trademarked terms into Google's Internet search engine, Google listed D's website as the second most relevant search result. Google also provided the searcher with a brief description of D’s website, and the description included these terms and highlighted them. D also represented in various ways that an affiliation exists between NASA and D or between NASA and D's DRX 9000. D also asserted in advertisements that the DRX 9000 is FDA 'approved.' P sued D and the district court issued a preliminary injunction prohibiting D from using P's trademarks within meta tags and prohibiting D from making the challenged statements about the DRX 9000. The district court specifically found that D's use of P's trademarks created a likelihood of confusion, and the court also found that D's advertising statements are literally false and material to consumers' purchasing decisions. D appealed. D contends that P failed to establish a substantial likelihood of success on the merits. D claims its use of the trademarks in invisible meta tags is not a 'use in commerce' and does not create a likelihood of confusion. D argues that the district court erred by categorically presuming that any plaintiff with a viable unfair competition claim will always suffer irreparable harm in the absence of a preliminary injunction.