US retail giant Walmart violated employees' rights by unlawfully threatening and firing workers who participated in strikes and other group protests, the National Labor Relations Board said Monday. The NLRB said it has found some merit in charges alleging that Walmart violated employee rights in 14 states and that it was prepared to issue complaints, unless the parties reach settlements in the cases. Among the charges, Walmart "unlawfully threatened, disciplined, and/or terminated employees for having engaged in legally protected strikes and protests," the federal agency said in a statement. The stores where the violations took place were in California, Colorado, Florida, Illinois, Kentucky, Louisiana, Maryland, Massachusetts, Minnesota, North Carolina, Ohio, Texas and Washington state. Other violations by Walmart, owned by Arkansas-based Wal-Mart Stores, occurred against employees taking "protected" actions in stores in California, Florida, Missouri and Texas. And ahead of the retailer's "Black Friday" sales day last year, Walmart used two national television news broadcasts and statements to workers at stores in California and Texas that unlawfully threatened employees with reprisal if they engaged in strikes and protests on November 22, 2012, the labor rights watchdog said. Organizers are planning new labor action for this year's Black Friday, the unofficial kickoff of the year-end holiday shopping season that follows the Thanksgiving Day holiday. Walmart, facing fierce competition in a lackluster economy, has moved up the start of this year's Black Friday by two hours, to 6:00pm, on Thanksgiving, November 28, slicing deeper into the holiday. "The fight for better pay, full-time work and an end to illegal retaliation at Walmart isn't just a workers' issue," Richard Trumka, president of the AFL-CIO, the largest federation of labor unions in the country, said in a statement. Trumka said it was a family and women's issue, an immigrant rights issue, a student issue, an environmental issue and a consumer issue, and above all, "an issue of fairness." "Black Friday is just the next step in efforts to stand together and demand Walmart makes the right choice. And until they do, the more than 12 million members of the AFL-CIO will stand in lockstep with the Walmart workers along their path to justice," he said.