As for the most recent VPN disruption, Golden Frog was one of the providers affected last week. While the company wouldn't reveal user numbers, a spokesman said that demand for its VPN was up in the country.
Part of the reason is that China in recent years has blocked other lower-quality VPNs that were free, pushing more customers to its service, said Golden Frog spokesman Andrew Staples in an email.
The company's service, called VyprVPN, is in use by business customers that need to access cloud services blocked in China, such as Google Docs and Dropbox, he added. But along with foreign students and other expatriates, Chinese citizens wanting access to an unfiltered Internet are also among its subscribers.
Although last week's disruption may have caused some hiccups for Golden Frog, the company was able to quickly restore its VPN service. "One reason we do well in the country is we've developed technologies for China," Staples said. The technology is called "Chameleon", and was built to "defeat" China's censorship systems, although its not 100 percent perfect yet, he added.
To fight back, China has blocked the websites to many of the top VPN providers. In some cases, e-commerce sites and social networking services in the country have censored search terms such as "VPN" and "Fanqiang", the Chinese word for climbing over the wall and circumventing the country's censorship.
Still, companies such as SaferVPN are finding ways to reach Chinese Internet users. They can do this by selling its services through affiliates and advertising networks that the censors haven't blocked yet. "Also when they block a domain name, we can just a start a new domain name," Bareket added.
But the big is question is how far China will go to stop the VPN providers. The government could do more to stifle the services, but any Internet clampdown would draw complaints from businesses about disruption of their activities, industry experts said.
For now, VPNs still have one other barrier to entry and that's the monthly subscription. Outside of China's larger cities, where many residents earn less, an unfiltered Internet could still be financially out of reach.
"What the authorities may be looking to do right now is make it more difficult for the masses to gain VPN access," said Mark Natkin, managing director for Beijing-based Marbridge Consulting. "But corporations and those that have enough money will still be able to use Facebook and Twitter."
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