Pittsburgh Steelers running back Rashard Mendenhall has filed suit against Champion sports apparel after the company terminated an endorsement deal over his comments on Twitter.

Following the announcement that Osama bin Laden had been killed, Mendenhall questioned public celebration over his death, tweeting, “What kind of person celebrates death? It’s amazing how people can HATE a man they have never even heard speak. We’ve only heard one side . . .” and opined on the Sept. 11 attacks, “We’ll never know what really happened. I just have a hard time believing a plane could take a skyscraper down demolition style.”

Mendenhall’s tweets received a large response, leading to a statement from the Steelers team president as well as a subsequent clarification by Mendenhall. Days later Champion terminated his deal. The company relied upon a reputation clause in the parties’ contract, which allowed the company to terminate the deal if Mendenhall “becomes involved in any situation or occurrence tending to bring [him] into public disrepute, contempt, scandal or ridicule, or tending to shock, insult or offend the majority of the consumer public.”

Mendenhall responded by filing a $1 million federal lawsuit, arguing that his termination was a breach of contract that violated his First Amendment rights. The suit argues that Mendenhall had used Twitter for several months with “the apparent assent” of the company to express his opinions and “foster debate” on various issues. For example, Mendenhall tweeted his agreement with fellow NFL running back Adrian Peterson comparing the League to “modern-day slavery” and also made comments about the opposite gender, tweeting that “Women are some of the most SELFISH creatures I know!” and “Women, if you don’t #respect your man someone else will.” In each instance, the company “at no time suggested that it disagreed with [Mendenhall’s] comments or that his tweets were in any way inconsistent with the values of the Champion brand,” according to the complaint.

To read the complaint in Mendenhall v. Hanesbrands, click here.

Why it matters: “This case involves the core question of whether an athlete employed as a celebrity endorser loses the right to express opinions simply because the company whose products he endorses might disagree with some (but not all) of those opinions,” Mendenhall’s complaint alleged. Despite the suit’s claim that Champion’s actions were unreasonable and contrary to the course of dealing between the parties, celebrities are often dismissed after generating controversy, even via Twitter. Both Michael Vick and Tiger Woods were dropped by sponsors when their off-field actions made headlines.