Microsoft employees have put forward a petition in defense of a trending GitHub repository they believe could be under threat of Chinese censorship. The repository, called 996.ICU, was established in late March by Chinese tech workers who were protesting extreme overwork. The stories name some of the biggest companies in China, including Alibaba, Huawei, ByteDance, DJI, Tencent, Vivo, and others.

The protest has enraged Chinese censors, and many local browsers are already blocking access to 996.ICU, including browsers from Tencent, Alibaba, Xiaomi, and Qihoo 360. Still, the repository remains available to Chinese users under alternate browsers, and GitHub has not moved to take it down.

There’s a real possibility that Microsoft, which owns GitHub, could be pressured into censoring the repository. The company continues to operate in China and censors search results on its search engine Bing to comply with local laws. So Microsoft employees are taking action to make sure that doesn’t happen.

The petition reads:

We, the workers of Microsoft and GitHub, support the 996.ICU movement and stand in solidarity with tech workers in China. We know this is a problem that crosses national borders. These same issues permeate across full time and contingent jobs at Microsoft and the industry as a whole. Another reason we must take a stand in solidarity with Chinese workers is that history tells us that multinational companies will pit workers against each other in a race to the bottom as they outsource jobs and take advantage of weak labor standards in the pursuit of profit. We have to come together across national boundaries to ensure just working conditions for everyone around the globe. We encourage Microsoft and GitHub to keep the 996.ICU GitHub repository uncensored and available to everyone. To other tech workers and industry supporters, we urge you to join us in our support of the 996.ICU movement.

Since 996.ICU is hosted on GitHub, the repository can’t be blocked at a network level without blocking the entire site, which would be catastrophic to Chinese software developers. Individual browsers can refuse to load the page, but those blocks are easy to circumvent by changing browsers. The ultimate decision of whether to risk China’s GitHub access falls to Microsoft, which so far hasn’t indicated a firm position on the protests.

This isn’t the first time that tech workers have petitioned for awareness of social issues, often to great success. The Google walkout in November over the company’s tendencies to protect and reward men accused of sexual harassment brought media attention to a serious issue and forced Google to agree to new policies regarding sexual harassment and diversity. Microsoft workers signed an open letter last June to protest the company’s work with Immigration and Customs Enforcement (ICE), saying they refused “to be complicit” with the Trump administrations immigration policies. Google employees also signed a letter last November pushing the company to cancel its plans for a censored search engine in China, a project that Google has now put on pause.