BEIJING • Enterprising Internet users in China fear the tools they use to tunnel through the country's "Great Firewall" may soon disappear, as Beijing tightens its grip on the Web.
Tens of millions of people are estimated to use virtual private networks (VPNs) to bypass Chinese restrictions - getting access to blocked websites such as Facebook and Twitter.
Beijing has for years turned a blind eye to these holes in its Great Firewall, but recent events suggest the virtual tunnels may soon be bricked up.
In January, China's Ministry of Industry and Information Technology announced it would be banning the use of unlicensed providers of the services.
In the months since the announcement, rumours have swirled that a crackdown was coming, but there was little clarity on what exactly the rule meant and how, or even if, it would be implemented.
In the past few weeks, however, omens of significant tightening seem to be everywhere.
Several luxury hotels in Beijing have said they will stop using the tools, which once provided unfiltered Internet as a convenience to their customers.
On Thursday, a cloud service provider in the capital notified users that it would practise shutting down and reporting VPN providers on the orders of Beijing's public security bureau.
Tech giants Apple and Amazon, too, have moved to limit their customers' access to the tools in China, in what has been seen as a voluntary move to get ahead of the impending crackdown.
Apple said it was removing a number of the applications from its app store, while Amazon's Chinese partner said customers would no longer be allowed to use "illegal" VPNs on its cloud service.
"There have been many rounds of government murmurings about VPN crackdowns, and foreign and Chinese businesses had grown used to only minor or temporary restrictions," said Mr Graham Webster, a senior research scholar at Yale Law School.
But this time it "appears (to be) different", he added.
For now, however, it still remains unclear who will be able to access VPNs and under what circumstances, a situation that has left both companies and regular users on tenterhooks.
Firms are casting around for information about the developments and have expressed alarm at the potential impact on the way they do business.
In a statement, the European Chamber of Commerce told Agence France-Presse it "has not seen any updated official document concerning restrictions on VPN use by companies", adding that in a recent survey of its members almost half expressed concern that the "continued strengthening of measures to tighten Internet control and access is having an even bigger negative impact on their companies".
"Our members' success depends on instantaneous access to information worldwide, and the ability to freely communicate with affiliates, suppliers and customers around the world," Mr William Zarit, chairman of the American Chamber of Commerce in China, said in a statement.
"Recent regulatory developments, including limiting VPN use, have created uncertainty for cross-border data communication," he said.
Analysts said Beijing was likely not looking to choke off VPNs completely, but was instead seeking to control them more tightly.
Mr James Gong, an expert on Chinese cyber law at Herbert Smith Freehills, said the regulations are not targeted at companies. The government can "shut things down, but that's not their purpose", he said.
Instead, "they want to drive all the traffic through the network operators so all of the connections will be transparent to them".
"It's highly unlikely that all VPN access would be eliminated," Yale's Mr Webster said, but added that the software might be increasingly "expensive and government-controlled" in the future.