The company changed its rules on external communications in September 2019 after the Amazon Employees For Climate Justice group revealed that it intends to walk out in support of the youth-led Global Climate Strike. Jeff Bezos listened and announced that Amazon will work towards relying solely on renewable energy by 2030 and having net zero carbon emissions by 2040. Shortly after that though, the tech giant introduced a policy that prohibits employees from publicly talking about the company's business without prior approval from management.

1/ Hundreds of us decided to stand up to our employer, Amazon. We are scared. But we decided we couldn't live with ourselves if we let a policy silence us in the face of an issue of such moral gravity like the climate crisis. #AMZNSpeakOut pic.twitter.com/zWIKku4LF6 — Amazon Employees For Climate Justice (@AMZNforClimate) January 27, 2020

Earlier this month, Amazon told at least two employees that they could be fired for publicly criticizing the company's environmental policies. They were accused of violating the company's external communications policy, because they provided quotes to The Washington Post about how Amazon's cloud computing business contributes to oil- and gas-company exploration. Members of the Amazon Employees For Climate Justice group asked their peers to speak up in support of those employees and to protest the company's communications rules.

They wrote in their letter calling for action:

"Don't get us wrong: some comms policies make a ton of sense (i.e. for confidential projects). But allowing a corporation to silence us on its contribution to the climate crisis is a clear overreach of comms policy, and effectively demands we give up our basic humanity and integrity in order to be employees. And, it's not just about climate: it's also about our ability to speak up on other issues like racism and sexism in tech, treatment of warehouse workers, donations to anti-LGBTQ politicians, and complicity with ICE."

Amazon says employees are free to talk about these issues with other employees and that they can voice their opinions at all-hands meetings and at lunches with executives. However, the company seems to be set on enforcing its external communications policies. Spokesperson Jaci Anderson told CNBC: