Google has fired a security engineer who updated a company tool to notify co-workers of their right to organize, spurring a labor complaint and adding to recent scrutiny of how the company has handled unionization efforts.

Kathryn Spiers, who worked as a security engineer, updated an internal Chrome browser extension so that each time Google employees visited the website of IRI Consultants — the Troy, Michigan, firm that Google hired this year amid a groundswell of labor activism at the company — they would see a pop-up message that read: “Googlers have the right to participate in protected concerted activities.”

Spiers was placed on administrative leave the week of Thanksgiving, the same week the company fired four other employees who claim Google has been engaged in illegal efforts to discourage workers engaged in organizing employees. She was fired Friday.

“We dismissed an employee who abused privileged access to modify an internal security tool,” a Google spokeswoman said in a statement, adding that it was “a serious violation.”

Spiers said she was acting in the interest of her co-workers.

“I was doing nothing more than notifying my co-workers about Google's obligations under labor law,” Spiers said in a text message. “Googlers are expected to take initiative and it's really important we hold upper management accountable."

I was fired last week by Google for organizing. All I did was make a popup to share the labor notice Google has to share with its workers.



3 hours later mgmt came to my desk, took my phone/laptop, escorted me away. I never got to say goodbye.



My story: https://t.co/dV4ExPHbLT — Kathryn Spiers (@eiais) December 17, 2019

The firing comes at a time of heightened tensions at Google as the company has been forced to reckon with employees’ discontent. Earlier this month, the National Labor Relations Board, or NLRB, opened an investigation into Google's firing of the four workers last month and whether Google discouraged employees from organizing.

Google workers have also organized internal petitions criticizing the company’s plans to build a censored search engine in China, as well as its cloud contract with the Department of Defense to build artificial intelligence for drones. Last year, Google employees organized a walkout across more than 40 offices to protest how they say the company has mishandled allegations of sexual assault and harassment within the company.

Spiers' pop-up message was inserted into a tool that notifies employees of privacy and security concerns about using non-Google tools and services, like warning employees not to upload proprietary information to Dropbox, Spiers said. The tool is managed by the platform security team, for which Spiers worked for almost two years as a security engineer.

Spiers told NBC News that she was inspired to create a digital notification because “a poster in the cafeteria is not the best way of reaching the majority of Googlers.”

The message included a link to a statement that the NLRB required the company to post for employees following the settlement of a complaint that was filed against Google in 2016.

Spiers, 21, said she went through the standard approval process, which requires two co-workers to greenlight changes, before updating the Chrome browser extension. Another source at Google familiar with the update approval process confirmed to NBC news that those two approvals are standard practice for a browser extension update.

Three hours after Spiers made the update, she was approached by members of Google’s internal security team and questioned before being placed on administrative leave, she said.

On Monday, a representative from the Communications Workers of America filed an NLRB charge against Google for Spiers’ termination, accusing it of interfering with her right to organize her co-workers.

“You’re allowed to put posters up on the wall to help organize your workers, and this can be seen as kind of a digital extension of that,” said Veena Dubal, a professor at the University of California’s Hastings College of the Law in San Francisco. “Whether or not you’re in a union or there’s a union being formed, the law protects organizing activities by employees in the workplace organizing to improve their working conditions.”