"If we discover (clients using unapproved VPNs), we will shut down services", said a member of staff at Beijing Sinnet Technology Co Ltd, which operates Amazon's cloud business, Amazon Web Services (AWS), in China.
"We're disappointed in this development, as it represents the most drastic measure the Chinese government has taken to block the use of VPNs to date", said ExpressVPN, "and we are troubled to see Apple aiding China's censorship efforts". "In the case of China, the law is very clear there".
In its fiscal third-quarter, Apple said revenue from Greater China was $8 billion, down 25 percent from the prior quarter and 10 percent from a year ago.
The recent removal of some VPN apps from Apple's App Store in China has prompted criticism, with some accusing Apple of bowing to pressure from Beijing and placing its business interests above its values. They are vital to hundreds of businesses, media organizations, research institutions and other groups that rely on the ability to connect with the wider internet.
The organization considers that the law is a "serious crack-down on the Internet freedom", "the last attack of the authorities on online freedoms".
This particular case, we're hopeful that over time the restrictions we're seeing are loosened, because innovation really requires freedom to collaborate and communicate. It seems that the emails from China's Ministry of Public Security are signs of the country's plans to widen the net of the Chinese firewall, even more worrying is tech companies willing to cooperate with the communist government's crackdown on their citizen's Internet access.
He explained that in 2015 the Chinese government "started tightening the regulations associated with VPN apps".
An Amazon spokeswoman said that Sinnet is in charge of guaranteeing that its customers in China follow the local laws and their notice was meant to remind their users of their responsibilities.
"Banning the "unauthorized" use of basic Internet security tools makes Russian Federation both less safe and less free", Snowden, who continues to reside in Russian Federation, wrote on his Twitter feed.
While Amazon and Microsoft both manage cloud services in China, homegrown rival companies such as Alibaba beat them in terms of size as the e-commerce giant has its own cloud services, which have developed at a fast pace in China.
Yokubaitis added, "We view access to the Internet in China as a human rights issue, and I would expect Apple to value human rights over profits". Software made by companies outside of China received messages from Apple over the weekend that their internet filters had been removed from China's mainland Apple App store.