Google is accused of creating an internal spy tool to monitor workers’ efforts to organize protests or discuss unions.

The alleged surveillance tool has been installed on employees’ computers as a Google Chrome extension and reports those who schedule a calendar event with more than 10 rooms or 100 colleagues, Bloomberg reported.

In a memo obtained by the outlet, an employee characterized the extension as “an attempt of leadership to immediately learn about any workers organization attempts.”

But the tech company said Wednesday that the allegations regarding the tool are “categorically false.”

“This is a pop-up reminder that asks people to be mindful before auto-adding a meeting to the calendars of large numbers of employees,” Google said in a statement.

The allegations come after Google contractors in Pittsburgh voted in September to join the United Steelworkers Union, CNet reported.

Another group of Google employees walked off the job in Mountainview, Calif., in November 2018 to protest the company’s handling of sexual misconduct claims.