But a new law that gives Hong Kong authorities sweeping powers to regulate online content could put those companies on a collision course with that censorship mechanism, known as the Great Firewall — and potentially force them out of Hong Kong altogether.
Under the national security law that went into effect last week, Hong Kong police can demand that online platforms and network providers take down content deemed a threat to China's security or restrict access to their services. If they fail to do so, company representatives could face nearly $13,000 in fines and six months in prison.
That has big implications for tech companies that use the city as a regional base thanks to its relative openness and proximity to China and the Asia Pacific region, even if its approximately 7 million residents don't make up a significant portion of their users.
"It is not a huge market, but is important symbolically," said Adam Segal, director of the digital and cyberspace policy program at the Council on Foreign Relations.
Caught in the middle
Companies are already reacting. Facebook (FB), Twitter (TWTR), Google (GOOGL) and Microsoft (MSFT) were among those declaring this week that they would temporarily stop honoring government data requests about their Hong Kong users, while TikTok — owned by Chinese company ByteDance — decided to shut down its platform there completely.
"Firms would be worried by the impact it has on their users, staff, and executives — as well as global concerns that they would be actively facilitating human rights abuse happening under that framework," said Raman Jit Singh Chima, Asia policy director at technology advocacy group Access Now. Chima and other experts say companies are likely to wait and see how far China will go in its crackdown on Hong Kong's internet, but exits from the city remain a possibility.
"They may wait to see if the government makes a request, but then they will be forced to decide, and leaving is likely," Segal said.
The vaguely worded law also has a provision that states it would also apply to offenses from outside the region "by a person who is not a permanent resident," potentially giving China the ability to take action against any post against Hong Kong on any platform, anywhere.
"I think that is meant to have a general chilling effect on people everywhere, not just not particularly high tech companies," said Scott Kennedy, an expert on China's economic policy at the Center for Strategic and International Studies.
And while that could lead to a degree of self-censorship overseas, Kennedy says there are questions about China's ability to actually enforce its rules on tech platforms outside its own territory.
"That's something that's a vast overreach by the Chinese, and I think they'd generate more pushback," he added.
Facebook, Twitter and Microsoft said they will continue to examine the law and its implications on their businesses.
"Our teams are reviewing the law to assess its implications, parti
