China has moved to outlaw the tools that allow internet users to get past the country's so-called "Great Firewall" of censorship measures.
Virtual private networks (VNPs) are pieces of software that disguise the location of an internet user. In this case, VPNs allow Chinese users to access websites that are restricted in the world's second-largest economy.
In rules laid out on Sunday by the Ministry of Industry and Information Technology in China, providers of VPN services will need to obtain government approval, a move that would make most of these programs illegal.
The Chinese government said the nationwide internet "clean-up" would run until March 31, 2018 and was aimed at strengthening "information security management".
"China's internet connection service market ... has signs of disordered development that require urgent regulation and governance," the ministry said.
The Great Firewall is a system of blocking content and websites, often that are critical of the government and its institutions. According to Greatfire.org, a website that tracks censorship in China, 173 of the world's top 1,000 domains are currently blocked in China.
Censorship is not unusual in China, but this latest round comes as the Communist party gears up for a leadership reshuffle this year.
CNBC has reached out to a handful of VPN services that operate in China and is awaiting some responses. NordVPN responded and said its service had not been affected.
"NordVPN does not have any servers in mainland China ... Users in China can still connect to NordVPN as usual. Due to strict regulations in China, connection procedures are not straightforward – users need to contact us directly and our team sets them up with a VPN connection," a spokesperson for NordVPN, told CNBC by email.
VyprVPN, which is run by a company called Golden Frog however, posted a blog in which it suggested that only providers operating from within China are likely to be affected. That means those VPN services that have servers outside of China could not see an immediate impact.
"Currently, VyprVPN continues to operate normally for our customers in China. Amidst these claims, it's business as usual for us here at Golden Frog – and for VyprVPN customers. Golden Frog is incorporated in Switzerland and does not operate any servers within China, so we are not subject to the harsh new regulations," the company said in a blog post on Monday.