Amit Bareket calls it a "cat-and-mouse" game. In this instance, his company is the mouse, and the Chinese government is a giant cat.
The two sides are continually at odds, because Bareket's company, SaferVPN, is one of many that provide software tools designed to circumvent the country's notorious Internet censorship.
These tools are growing more popular in China, in spite of recent government attempts to block them, according to Bareket.
"I can tell you that more than 300 new VPN users come to our service every day in China," said Bareket, who is the spokesman at SaferVPN.
VPNs, which stand for Virtual Private Networks, are essentially tools that can let users bypass Internet censorship. For about US$6 to $10 a month, subscribers to these services in China can access blocked sites such as Facebook, YouTube and more.
But lately, China has been more aggressive in trying to disrupt these services. Last week, several VPN providers reported access problems for users. Days later, one of the country's top regulators defended the actions and signaled that the authorities were prepared to crack down further.
"As the Internet develops, and new circumstances arise, we will take new regulatory measures to keep up," said Wen Ku, a director with China's Ministry of Industry and Information Technology.
That said, the recent disruptions haven't stopped the VPN services, only added a minor roadblock. Companies like SaferVPN still manage to bring their services to the country, and are working on new technologies to stay a step ahead of the censors.
Although VPN providers serve countries across the world, China is one of the big markets, Bareket said. SaferVPN is a smaller player, and has only several thousands of users from the country. Bareket estimated that the bigger VPN providers may have over 100,000 users in China, if not more.
In SaferVPN's case, it's not just foreigners living in China and businesses that use its service, but also local residents. VPNs became more widespread among Chinese users last year, driven mainly by regular users wanting access to site likes Facebook, Bareket said.
That may be the reason why the government, which was previously somewhat tolerant of the technology, is growing more alarmed about VPN usage.
VPNs risk upending the vast censorship China has so heavily invested in. Bareket noted that Chinese authorities were taking more measures to block VPN service, after pro-democracy protests broke out in Hong Kong last September.
China was already censoring coverage of the event, and was quick to cut access to Instagram, after photos of the demonstrations began to appear online. Still, a VPN service would be able to bypass the block.
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."