SAN FRANCISCO (AP) — Four workers fired from Google last week are planning to file a federal labor complaint against the company, claiming it unfairly retaliated against them for organizing workers around social causes.

The former employees said Tuesday they are preparing to file unfair labor practice charges with the National Labor Relations Board this week. All four were fired Nov. 25 for what Google said were violations of its data security policy.

Company officials wrote in a memo — without confirming the employees' names — that the four were "searching for, accessing, and distributing business information outside the scope of their jobs."

But the four workers — Laurence Berland, Sophie Waldman, Rebecca Rivers and Paul Duke — say they believe they did not violate company policies and claim that Google is using the alleged violations as an excuse to terminate them for labor activity.

"This is an expression of Google's management power," Duke said. "They are scared of worker power."

Google employees are known for being some of the most outspoken across the tech industry. Thousands of employees walked out of work last year to protest the company's handling of sexual misconduct claims, in what became known as the Google Walkout. Since then, employees have petitioned for better benefits for contract workers, successfully argued for the end of mandatory arbitration and have opposed Google's involvement in some government projects.

The company has also been known for an open, collaborative work culture since its early days, one that employee activists say is now getting closed off.

Google recently changed its weekly employee live Q&A with CEO Sundar Pichai to a monthly meeting. It has also updated its community guidelines to tell employees to avoid "disrupting the workday" to debate politics or other topics — both moves that some workers say are meant to discourage open speech and crack down on employee pushback.

Waldman and Duke helped create a petition earlier this year that called for Google to refrain from bidding on a cloud computing contract with U.S. Customs and Border Patrol. Nearly 1,500 employees signed the petition, which said CBP had "engaged in human rights abuses" at the southern border and that Google should not work with the agency.

Rivers and Berland also helped spread the petition, and Berland has been involved in organizing other campaigns at the company, including those involving LGBTQ rights.

All four say they were questioned by Google officials in the past few months for sharing or accessing internal documents. Two say they were placed on administrative leave last month.

The company said it found one worker set up notifications to be alerted about other employees' calendar changes, which made those employees feel unsafe. It said screenshots of their calendars with their names were shared externally.

The employees said any documents they viewed and shared were already accessible by Google workers, and they only shared them internally. They said others later shared them outside the company.

"We have always taken information security very seriously, and will not tolerate efforts to intimidate Googlers or undermine their work, nor actions that lead to the leak of sensitive business or customer information," the memo sent by Chris Rackow, Royal Hansen and Heather Adkins from the company's security and investigations team read.

The four fired workers said they received no severance payments. They are working with lawyers and have not yet determined the details of the NLRB complaint, but said it will address retaliation concerns and will likely take issue broadly with Google's recent policy changes and alleged crackdowns against employee organizing.

Google reached a separate settlement with the NLRB in September over employees' ability to speak out about workplace issues. Google agreed to post notices to remind employees of their rights, including the ability to talk to each other about workplace conditions and push for changes such as raises.

The situation of the four workers has led to additional protest. A few hundred people attended a rally at Google's San Francisco office in November to call for Rivers' and Berland's reinstatement.