Another worker is accusing Google of unfair labor practices after being fired for creating a browser pop-up that could be seen by the company’s employees. It read: “Googlers have the right to participate in protected concerted activities.”

Google, which is already facing charges of anti-union retaliation after it fired four employees before Thanksgiving, is now facing a similar charge brought by Kathryn Spiers, a security engineer who was fired Friday. A filing by the Communications Workers of America with the National Labor Relations Board, which was seen by this news organization, said Spiers’ job responsibilities included notifying employees of their rights to protected activity as required by previous NLRB charges against Google.

“This kind of code change happens all the time,” Spiers said in a blog post on Medium. “For example, someone changed the default desktop wallpaper during the walkout last year so that the Linux penguin was holding a protest sign.”

In an interview with this organization Tuesday, Spiers — who in her two years with the company also protested against Project Maven (Google’s AI contract with the Pentagon) and other issues — said she hoped that being open about her firing will help Google workers feel unafraid of continuing to speak up.

“There is this weird duality of actions that Google has taken that has scared some people into silence and scared some people into action,” Spiers said, adding that she hoped to be reinstated. “I still have good that I can be doing at Google.” .

In an unusual move by Google — which has not confirmed the names of any workers it has fired — a company spokeswoman on Tuesday provided a copy of an email by Royal Hansen, vice president of Technical Infrastructure Security & Privacy, saying Spiers acted without authorization.

“She misused a security and privacy tool to create a pop-up that was neither about security nor privacy,” Hansen said in the email. “The issue here was not that the messaging at issue had to do with the NLRB notice or workers’ rights. Our analysis would have been the same had the pop-up message been on any other subject — even a joke.”

Other former Googlers, some of whom were fired or forced out, disagree.

Meredith Whittaker, co-founder and co-director of AI Now Institute at New York University and one of the organizers of the Google Walkout who left the company over the summer, also mentioned the Linux penguin and tweeted Tuesday: “This is BS … There’s a long tradition of Google (engineers) taking initiative to create features and tools that help surface info and improve workflow. Kathryn was punished for organizing. Full stop.”

Whittaker and others said they faced retaliation for organizing last year’s walkout, which was a protest by thousands of Googlers around the world over the company’s handling of sexual misconduct accusations against its executives. Since then, Google workers have engaged in various protests and actions related to issues ranging from YouTube’s handling of LGBTQ harassment to the company’s choices of voices for an AI ethics panel to its bidding for a contract with Customs and Border Protection.

The company recently hired IRI Consultants, which is known for its anti-union work, and Spiers said in her blog post that she created the pop-up message to appear when Googlers visited the website of that company or Google’s community guidelines policy.

As for Google commenting on Spiers’ firing, Catherine Fisk, a professor at UC Berkeley School of Law, pointed out that in the case of the four workers Google fired last month, the company cited sharing confidential company information as one cause.