The National Labor Relations Board Office of the General Counsel filed a complaint on Wednesday because Walmart violated the labor rights of employees who participated in protests against Walmart in 13 states. Last year saw widespread Walmart employee protests as workers went on strike because of low wages and poor working conditions.

In 2013, Walmart retaliated against employees with illegal firings, disciplinary actions, or threats of both, which violated employee labor rights. The General Counsel originally attempted to file a similar complaint in November but delayed filing pending the outcome of settlement negotiations with Walmart. The negotiations failed, and the General Counsel filed the consolidated complaint.

No hearing date is set, but Walmart must respond to the complaint by January 28. The consolidated complaint was filed on behalf of 60 workers, and 19 of those workers were allegedly fired because of participating in protests. The National Labor Relations Act protects employees from employer retaliation against workers who engage in worker-concerted activities. Concerted activities include open discussion of workplace conditions, petitions, and protests.    

In November 2012, Walmart spokesman David Tovar threatened Walmart employees on CBS News after word of impending strikes to take place on Black Friday of that year surfaced. During his network appearance, he said employees who participate in the strikes could suffer “consequences.”

In the original complaint, the NLRB ruled that Walmart broke the law when a total 117 workers were dealt retaliation for their participation in the 2012 Black Friday protests. But Tovar’s threats were not enough to prevent workers and labor rights activists from protesting at over 1,000 Walmart locations that year.

The following year saw an even larger turnout. OUR Walmart, an activist group for Walmart employees, organized a nationwide strike at more than 1,500 locations in 2013. The group called it the “largest mobilization of working families in recent history.” The planned strikes put so much pressure on Walmart that the company requested judges in two states to ban protesters’ entry into the stores.

If an administrative judge finds Walmart liable for the violations, the company will have to compensate the affected workers with back pay and reinstate their employment.

“We’ve never seen a complaint against Walmart of this size or scope, and we’re glad the NLRB is taking action,” said Sarita Gupta, executive director of Jobs With Justice, one of the groups critical of Wal-Mart. “Walmart’s attacks on its own employees cannot go unchecked.”

Josh is a writer and researcher with Ring of Fire. Follow him on Twitter @dnJdeli.