People in the Chinese megacity Chongqing could be fined for using VPNs to jump over the country's "Great Firewall" that blocks access to forbidden websites from Google to Facebook.
The punishment would be meted out to people using virtual private networks to access banned sites for commercial purposes, but Amnesty International said the wording was vague enough that it could affect any business or individual.
Anyone who skirts censorship controls in the southwestern metropolis of 30 million people will receive a warning to disconnect from the internet, the Chongqing government said Monday.
Those who make a profit of more than 5,000 yuan ($730) while using VPNs will be fined 5,000-15,000 yuan, according to the updated internet security regulation which came into effect in July but only announced this week.
The move is a departure from authorities' previous approach of reinforcing the government's "Great Firewall" to block VPN providers, who provide virtual tunnels that allow users to evade China's vast censorship system.
"It looks like such practices might be extended to other parts of China if Chongqing police succeed in punishing people using VPNs," Amnesty International's China researcher Patrick Poon told AFP.
In January Beijing launched a campaign to crack down on such tools.
While China is home to the world's largest number of internet users, a 2015 report by US think tank Freedom House found that the country had the most restrictive online use policies of 65 nations it studied, ranking below Iran and Syria.
But China has maintained that its various forms of web censorship are necessary for protecting its national security.
Sites blocked due to their content or sensitivity, among them Facebook, Twitter, Google Search and Gmail, cannot be accessed in China without VPNs.
The national VPN crackdown and Chongqing campaign come after the passing of a controversial cybersecurity bill last November that tightened restrictions on online freedom of speech and imposed new rules on service providers.
Earlier this month, Beijing said it would push a "China solution" to global cyber governance after releasing a strategy paper outlining a vision of the web where individual countries control the information that flows across their borders.