(This March 31 story has been corrected to clarify that the labor agency is alleging that Activision violated the law but has not yet issued a final ruling in the headline and paragraph 1, to fix the name of the union to say 'Communications Workers of America' in paragraph 3, and to add that the election petition by Boston workers was withdrawn in paragraph 12)
A U.S. labor agency on Friday alleged that Activision Blizzard Inc violated federal labor law by illegally surveilling employees during a walkout and threatening to shut down internal chat channels as a union sought to organize its workers.
A National Labor Relations Board spokeswoman said that unless Activision settles, the agency will issue a complaint against the company involving employees of its subsidiary Blizzard Entertainment Inc based in California and three other states.
The Communications Workers of America union (CWA) has accused the "Call of Duty" maker of a series of illegal labor practices at the union has sought to organize video game testers and other employees at the company and its subsidiaries.
Blizzard employees around the country staged a walkout last year to protest what they said was a lack of gender equality at the company.
Kayla Blado, a spokeswoman for the labor board, said on Friday that a regional agency official had found merit to the CWA's claim that Activision used security staff to keep tabs on workers during the walkout.
A claim that the company also broke the law by threatening to close internal Slack channels where employees frequently discussed working conditions was also found to have merit, Blado said.
An Activision spokesperson in a statement defended the company's ability to prevent "toxic workplace behavior."
"CWA wants us to accept their ... false claims, but we strongly believe employees shouldn't have to be subjected to insults and put downs for their hard work – especially on company communication platforms," the spokesperson said.
The CWA in a statement said Activision's conduct showed a clear pattern of disregard for workers' legal rights.
"In spite of Activision Blizzard's anti-union efforts, workers continue to organize, speak out about their working conditions and win union campaigns," the union said.
Activision is already facing a separate NLRB complaint issued last year claiming the company used a policy limiting what workers can post on social media to bar them from discussing working conditions. Activision has said its social media policy is lawful and does not bar employees from exercising their rights under U.S. labor law.
Small groups of workers at Activision subsidiaries in New York and Wisconsin have voted to join the CWA in recent months. Activision has said it is considering its options in those cases. Boston-based employees of Activision unit Proletariat in January withdrew a petition to have an election.
Xbox maker Microsoft Corp last year agreed to buy Activision for $69 billion, a deal that has faced antitrust scrutiny from U.S. and European regulators.