Such messaging helps to mobilize Chinese communities, especially newly arrived migrants in Australia, Canada, the United States and elsewhere, to support the official line from Beijing. One website for a planned protest this weekend in Sydney asks Chinese to stand together against “rioting” in Hong Kong, which it said was causing discrimination against Chinese in Australia.

The battle over Hong Kong is, in effect, being exported, pitting overseas Chinese communities against each other. Over the past few weeks, “Lennon Walls,” covered in colorful Post-it notes expressing support for Hong Kong, have been torn down by supporters of Beijing from Auckland, New Zealand, to Vancouver, British Columbia, and from Hobart, Australia, to Harvard Square. After a violent tussle between pro-China and pro-Hong Kong students in late July at the University of Queensland in Australia, the Chinese consul-general in Brisbane, Xu Jie, issued a statement praising the “spontaneous patriotic behavior of Chinese students.”

One reason this conflict is playing out on social media is that almost all of Hong Kong’s big media companies are owned by mainland business executives or groups with extensive business interests in China, so they have instinctively taken a pro-Beijing stance. This has left digital news outlets and the overseas media as the front line in the battle for public opinion. People trying to livestream the protests and foreign media are apparently already being targeted by the police. In recent weeks, a BBC journalist was saved from injury only by his face mask, which shattered when the police shot directly at his head. Another reporter wearing a bright yellow press vest was crushed against a wall by three police officers. Two journalists were attacked by a gang of street thugs, and a well-known British livestreamer scratching his belly was publicly accused by a pro-Beijing politician of being a “foreign commander” sending hand signals to protesters. Such an accusation would be laughable had it not been so widely shared.

To counter what they say are lies and malicious distortions, the protesters have started to hold regular news conferences, with their representatives addressing the media wearing face masks and yellow helmets. The movement’s social media strategy has been to use colorful memes and videos tailored for different audiences, including large-print messages with floral backgrounds for elderly readers.

In recent days, the state-run Chinese media has begun sharing videos showing large-scale exercises featuring the People’s Armed Police, a paramilitary group, in the city of Shenzhen, over the border from Hong Kong. The same group, instead of the People’s Liberation Army, was used to crack down on protests in Chengdu in 1989. Hong Kongers may dismiss these provocations as bluffing, but it is a clear sign that the information war, like the battle for Hong Kong itself, is set to escalate further.

Louisa Lim (@limlouisa) is a senior lecturer at the Center for Advancing Journalism at the University of Melbourne, Australia, and the author of “The People’s Republic of Amnesia: Tiananmen Revisited.”

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.

Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram.