T-Mobile US, Inc., fka T-Mobile USA, Inc., et al. v. Simply Wireless Inc.

Under the Lanham Act, an unregistered common law mark must be in “use[]” in order to be protectible. 35 U.S.C. § 1127 (2006). This case arises from Respondent’s efforts to enforce a purported common law trademark that it concededly did not use for years at a time and was not using at the time Petitioners began the activities that Respondent contends constitute trademark infringement. The Fourth Circuit panel in this case held that “use” under Section 1127 of the Lanham Act need not be continuous, and that once common law trademark rights are established through use over some unspecified period of time in the past, those rights persist until abandoned as defined by Section 1127. The question presented is: Whether the “use” that creates a common law trademark right under Section 45 of the Lanham Act, 35 U.S.C. § 1127 (2006), must be continuous—at least up until the point at which the trademark defendant begins the assertedly infringing activities—for the purported holder of a common law trademark to maintain its rights and preclude another from use. (i)