the study drove a backlash against facial recognition technology and, particularly, its use in law enforcement. Microsoft’s chief legal officer said the company had turned down sales to law enforcement when there was concern the technology could unreasonably infringe on people’s rights, and he made a public call for government regulation.

Twelve months later, Microsoft backed a bill in Washington State that would require notices to be posted in public places using facial recognition and ensure that government agencies obtained a court order when looking for specific people. The bill passed, and it takes effect later this year. The company, which did not respond to a request for comment for this article, did not back other legislation that would have provided stronger protections.

Ms. Buolamwini began to collaborate with Ms. Raji, who moved to M.I.T. They started testing facial recognition technology from a third American tech giant: Amazon. The company had started to market its technology to police departments and government agencies under the name Amazon Rekognition.

Ms. Buolamwini and Ms. Raji published a study showing that an Amazon face service also had trouble identifying the sex of female and darker-​skinned faces. According to the study, the service mistook women for men 19 percent of the time and misidentified darker-​skinned women for men 31 percent of the time. For lighter-​skinned males, the error rate was zero.

New York Times article that described it.

In an open letter, Dr. Mitchell and Dr. Gebru rejected Amazon’s argument and called on it to stop selling to law enforcement. The letter was signed by 25 artificial intelligence researchers from Google, Microsoft and academia.

Last June, Amazon backed down. It announced that it would not let the police use its technology for at least a year, saying it wanted to give Congress time to create rules for the ethical use of the technology. Congress has yet to take up the issue. Amazon declined to comment for this article.

Dr. Gebru and Dr. Mitchell had less success fighting for change inside their own company. Corporate gatekeepers at Google were heading them off with a new review system that had lawyers and even communications staff vetting research papers.

Dr. Gebru’s dismissal in December stemmed, she said, from the company’s treatment of a research paper she wrote alongside six other researchers, including Dr. Mitchell and three others at Google. The paper discussed ways that a new type of language technology, including a system built by Google that underpins its search engine, can show bias against women and people of color.

After she submitted the paper to an academic conference, Dr. Gebru said, a Google manager demanded that she either retract the paper or remove the names of Google employees. She said she would resign if the company could not tell her why it wanted her to retract the paper and answer other concerns.

Cade Metz is a technology correspondent at The Times and the author of “Genius Makers: The Mavericks Who Brought A.I. to Google, Facebook, and the World,” from which this article is adapted.

View Source