Microsoft employees are protesting against the company’s alleged failure to stem gender discrimination and sexual harassment, according to reports.

A group of Microsoft employees dressed in all white challenged the company’s chief executive, Satya Nadella, and top human resources executive, Kathleen Hogan, over the company’s treatment of women at a Q&A session on Thursday, according to Wired. The all-white outfits were a reference to the US congresswomen who wore white during Donald Trump’s State of the Union address this February.

The protest followed weeks of internal discussion about sexism on an email thread that began on 20 March, when a female employee who had been in the same position for six years asked other women for advice on advancement, according to Quartz.

Dozens of female employees of the company responded by sharing their experiences of harassment and discrimination on the email thread.

“This thread has pulled the scab off a festering wound,” one employee wrote, according to Quartz. “The collective anger and frustration is palpable. A wide audience is now listening. And you know what? I’m good with that.”

Another employee alleged that it was common for female employees to be “called a bitch at work”, and a third said she was twice asked to “sit on someone’s lap” during a meeting when executives and HR representatives were present.

Hogan joined the email thread, and Microsoft provided her email as comment.

“We are appalled and sad to hear about these experiences,” Hogan wrote. “It is very painful to hear these stories and to know that anyone is facing such behavior at Microsoft. We must do better.”

The executive wrote that the company’s chief diversity officer would be holding sessions to hear feedback in April, and invited employees to report negative experiences directly to her.