The National Labor Relations Board (NLRB) filed a complaint against Google Wednesday alleging that the company illegally spied on and then fired two employees for organizing.

The complaint says that Google violated labor laws by surveilling and terminating Laurence Berland and Kathryn Spiers, both former engineers at the company’s San Francisco office, in 2019.

Berland was fired after organizing against Google’s decision to hire the notorious union-busting firm IRI Consultants. He had found out about the work with IRI from colleagues’ calendar events, which Google claimed was in violation of their policies.

“Google’s hiring of IRI is an unambiguous declaration that management will no longer tolerate worker organizing,” he said in a statement Wednesday. “Management and their union busting cronies wanted to send that message, and the NLRB is now sending their own message: worker organizing is protected by law.”

Spiers had created a pop-up for Google employees visiting IRI’s website that reminded them of their “right to participate in protected concerted activities.”

“This week the NLRB issued a complaint on my behalf,” she said. “They found that I was illegally terminated for trying to help my colleagues.”

Google has previously defended the firings, arguing that the two workers had violated company policy.