In a post on Medium, Spiers says that Google was recently forced to a publish a list (by the NLRB), internally, outlining the rights its employees have. And in order to ensure that all affected employees knew about it, Spiers added a pop-up notification to the company’s internal Chrome browser. Apparently this is a common practice inside the company, allowing people to share “hobbies or interests.”

In response to a request for comment, a Google spokesperson said that it had “dismissed an employee who abused privileged access to modify an internal security tool. This was a serious violation.”

“When I heard that Google had hired a union-busting firm and started illegally retaliating against my coworkers,” writes Spiers, “I decided to make sure that my coworkers knew about the [list].” Spiers is referring to Google’s recent hiring of IRI Consultants, a company described by the New York Times as an “anti-union consulting firm.” When Google employees visited IRI’s website, or the internal guidelines, a pop-up would read “Googlers have the right to participate in protected concerted activities.”

Spiers says that Google’s response was to suspend her immediately, and call her into “interrogations” where she was aggressively asked about “other organizing activities.” She says that her treatment was “extremely aggressive and illegal,” and Google did not allow her to speak to a lawyer or other representative. On December 13th, she was fired for “violating Google’s security policies,” but no explanation as to how was given.

This part of a growing culture of discontent inside Google which seems to be spilling over into outright hostility between management and employees. In November, four employees were fired, Google says because they were caught committing “clear and repeated violations of data security policies.” The victims, however, feel they were fired in retaliation for attempting to organize protests against problematic government contracts.

Google’s role has come under increased scrutiny by its employees, especially around some of its plans to work with China, the defense department and CBP. The company has also seen walkouts after details leaked that Andy Rubin, who allegedly left the company after he carried on an inappropriate relationship with a subordinate, was given a $90 million golden parachute. Google’s famously open culture is apparently contracting, and the company recently ended its practice of weekly town-hall meetings in which employees could ask leaders questions.

The four employees, who were fired at Thanksgiving, are all filing unfair labor practice charges with the National Labor Relations Board, claiming the firings are attempts to prevent organizing. Spiers also alleges that a senior Google employee signed a letter “falsely accusing four of my coworkers,” a reference to the “Thanksgiving Four.” The NLRB has pledged to investigate the firings.

The four employees claim they were fired for protected labor organizing. Last week, they filed unfair labor practice charges.

Google says it fired the four over repeat violations of its data security policies. In a statement provided to Engadget it said:

“We dismissed four individuals who were engaged in intentional and often repeated violations of our longstanding data security policies, including systematically accessing and disseminating other employees’ materials and work. No one has been dismissed for raising concerns or debating the company’s activities.”

This isn’t the NLRB’s first Google investigation. A few months ago, as part of a settlement with the agency, Google agreed to remind employees they can freely discuss workplace issues and that they do not have to “avoid controversies that are disruptive to the workplace.” In other instances, the NLRB has backed Google’s decisions, like the one to fire the diversity memo writer James Damore.

The current investigation is expected to take about three months. Regardless of the outcome, this case is the latest in a string of accusations that Google has a retaliation culture.