San Francisco — Meredith Whittaker, who helped lead employee protests at Google over the search giant’s military work, artificial intelligence and policies, is leaving the company.

In a blog, she warned that the internet giant’s AI software and huge computing resources are helping it expand in unsettling ways.

“Google, in the conventional pursuit of quarterly earnings, is gaining significant and largely unchecked power to impact our world (including in profoundly dangerous ways, such as accelerating the extraction of fossil fuels and the deployment of surveillance technology),” she wrote in a blog on Tuesday. “How this vast power is used — who benefits and who bears the risk — is one of the most urgent social and political (and yes, technical) questions of our time.”

Whittaker helped spark a broader uprising among workers at some of the world’s largest technology companies, including Alphabet’s Google, Microsoft  and Amazon.com. They are concerned these corporations are gaining too much power through AI-powered, machine-based decision making that has flaws and little or no accountability.

Over the past year, some staff at Google erupted in protest, prompting the company to drop a Pentagon AI contract and a censored search project in China.

Whittaker, who led Google’s Open Research group, was one of the most outspoken voices. She was one of six women who organised massive walkouts after reports that Google paid handsome sums to executives accused of sexual harassment.

Other Google protesters were saddened by Whittaker’s resignation, but hopeful that their attempts to hold large tech companies accountable will continue.

“Our movement has moved into a new phase,” said Irene Knapp, a senior software engineer at Google. “Those of us who remain at the company have been focused on disseminating knowledge and teaching our organising skills to new people. I am sure that Meredith would not be leaving if she didn’t know that she’s accomplished that, and I know that I very much feel she has. We’re set up for the long haul.”

While at Google, Whittaker also served with AI Now, an ethics organisation affiliated with New York University that she co-founded. The group often criticises businesses and government agencies for using AI systems, such as  facial recognition, in policing and surveillance. Whittaker also publicly denounced some Google decisions, including the appointment of Kay Coles James, a conservative think tank leader, to an AI ethics board. Google soon nixed the board.

“People in the AI field who know the limitations of this tech, and the shaky foundation on which these grand claims are perched, need to speak up, loudly. The consequences of this kind of BS marketing are deadly (if profitable for a few),” Whittaker wrote on Twitter on Sunday.

In April, about six months after the big employee walkout, Whittaker and another protest leader, Claire Stapleton, said the company was retaliating against them for their role in the activity. In an e-mail to colleagues, Whittaker said her Google manager told her to “abandon [her] work on AI ethics” and blocked a request to transfer internally. At the time, Google denied it retaliated against Whittaker.