US tech giants drew a line in the sand earlier this week when they announced that they would suspend cooperation with requests from Hong Kong law enforcement for access to user data. In so doing, however, they may have also effectively drawn a line under the period of relatively free and open internet in Hong Kong.

In a seemingly coordinated move, Google, Facebook and Twitter made similarly worded announcements that they are temporarily stopping the processing of requests from Hong Kong authorities, as they assess the implications of the national security law. Microsoft and a number of smaller companies including LinkedIn and Zoom have also said they will suspend or halt cooperation with Hong Kong authorities. The tech companies have cited concerns about freedom of expression, surveillance and censorship under the new legal regime. Although the companies have phrased this as a temporary measure, it’s hard to see how those concerns can be resolved—and, therefore, it’s hard to see how or when the companies will be able to operate again in Hong Kong.

The companies’ decisions are likely to reflect a combination of political judgement and pragmatic calculation that the day is coming when they and others will be forced to choose between operating in the Chinese domestic market, now including Hong Kong, or in major Western markets, particularly the Five Eyes countries (Australia, Canada, New Zealand, the United Kingdom and the United States).

The recent scandal surrounding Zoom’s decision to cut off Chinese human rights activists’ access to its services, in compliance with Chinese law but to the outrage of many in the West, is no doubt fresh in the minds of many tech executives. The episode underscores the shrinking space for tech companies seeking to walk on both sides of the fence, by obeying Chinese law in China while purporting to uphold democratic rights and values in other jurisdictions.

The national security law is likely to speed up this process of technological bifurcation, driving deeper cracks through the splinternet. For tech companies, the new law has forced a grim recognition: the Great Firewall is coming for Hong Kong, and tech companies which cannot or will not flourish inside that walled garden will be weeded out sooner or later.

For some, particularly those with relatively little to lose, taking a swift moral stand and walking out with their heads held high is clearly seen as preferable to trying to cling on. For others, the situation is more complex. Pressure is building on Apple, which has both a bigger proportion of its supply chain and a far larger market presence in mainland China than companies like Facebook or Twitter. Historically Apple has often sided with Hong Kong’s authorities over democracy protesters, including removing their apps from its App Store.

In contrast to other platforms, Reddit—which received a US$150 million investment from Chinese tech giant Tencent last year—has said that it will continue to comply with data requests from Hong Kong authorities.

It’s not just Western companies which sense the grinding foundations of the Great Firewall expanding to encompass Hong Kong. The swift announcement from ByteDance’s TikTok that it will be leaving Hong Kong entirely ‘within days’ implies a recognition that Hong Kong is now effectively the territory of its sister app Douyin, which serves the Chinese mainland market, and that continuing to operate in Hong Kong would pose a risk to TikTok’s already imperiled future overseas.

The implications of the national security law will also spread beyond communications platforms. Companies with physical internet infrastructure based in Hong Kong are now faced with difficult decisions. A Telstra spokesperson told the Sydney Morning Herald that the company is considering the future of its data centre in Hong Kong, given that the law compels it to hand over data to the Chinese government if requested.

Likewise, the ability of Hong Kong–based tech companies to continue to promote themselves to international consumers as providing privacy or security, at least from the Chinese government, is also very much in doubt. Non-Chinese customers of these companies will have to factor in the risk that their data could end up in the hands of Chinese authorities.

For the democracy protestors of Hong Kong, the decision taken by the US tech platforms to protect their data from law enforcement is a Pyrrhic victory. In practice, and despite the efforts of many to retrospectively scrub their online footprints, there is likely to be more than enough digital evidence available to Hong Kong law enforcement from other sources to wield against protestors should it choose to do so. The seemingly inevitable retreat of Western internet platforms and technology companies marks the end of an era as, brick by brick, the Great Firewall is built up around Hong Kong.