A Google engineer says she’s been illegally fired for participating in union organizing efforts, the latest in a string of similar claims made over the past month. 

Kathryn Spiers, who’s filed a complaint with the National Labor Relations Board, wrote in a blog post that she created a modification for the employee version of the Google Chrome browser that would inform employees of their rights to discuss their working conditions when they visited the website of a famously anti-union law firm Google has retained. Her NLRB complaint alleges unlawful termination, according to a screenshot posted to Twitter.

“Google has overreacted in an egregious, illegal, and discriminatory manner,” she said.

Spiers said she had worked at Google for just under two years and received high marks in performance reviews, so the discipline—she said Google investigators interrogated her for hours and denied her access to a lawyer—came as a shock. Part of her job on the Platform Security team, she said in the post, had been creating browser notifications for employees using Chrome. 

Royal Hansen, a vice president of technical infrastructure for security and privacy, wrote in an email that went out to all Google employees, “I want to be very clear: the issue was not that the messaging had to do with the NLRB notice or workers' rights.”

“Here, she misused a security and privacy tool to create a pop-up that was neither about security nor privacy,” he said.

Spiers is the fifth employee in the past month to allege that Google retaliated against her. Four were fired in late November—one had protested against Google’s work with Customs and Border Patrol, another against YouTube’s hate speech policies.

The company, once famous for its transparent and freewheeling culture, is undergoing a seismic shift in employee relations, precipitated by a series of scandals, as its leadership shifts. Founders Larry Page and Sergey Brin stepped down as leaders of Google parent company Alphabet this month, ceding control to Google CEO Sundar Pichai.