China's online censorship is getting more sophisticated: blocking common code words and images used by citizens on social media platforms to discretely signal their opposition to China's increasingly authoritarian government.
Last week, the Chinese government tweaked its constitutional laws to enable President Xi to hold office indefinitely. Usually, the country's presidents cannot stay in power for more than 10 years.
Although China's ruling Communist Party naturally backs the move, the general public is less uncritical. But due to strict censorship laws, expressing these concerns unambiguously could get Chinese citizens into trouble with the authorities.
However, according to new research from security organisation SANS Institute, people have been using code words such as "Winnie Pooh" and images of the cartoon character to refer to Xi.
Users of WeChat in other countries are not affected, even if they are in the same chat room as Chinese users
But it is now believed that government officials have detected this trend and begun using AI-driven tools to better detect these code words and images used on Chinese social-media platforms.
"Chinese censors have long had a pretty tight grasp on social media in the country in order to curb any dissent," said Johannes Ullrich, dean of research at SANS.
"For example, Chinese censors, in cooperation with service providers in China, have used automated tools that eliminate certain key terms from social media discussions. But we all know that signature-based filtering of known bad words is tricky."
He added that people in China still turned to services, such as WeChat, to express their opposition, but doing so in more subtle ways. "Winnie the Pooh is used instead of images of Xi due to their apparent resemblance to each other," suggested the academic.
Hence, Chinese officials have now blocked images of the bear, though. But that has not stopped people from coming up with other tactics to express their dissent.
"Another evasion technique is derived from Chinese comedy. Chinese jokes often use wordplay by replacing words with others that "sound alike" (homophones) taking advantage of different tones used in Chinese," said Ullrich.
It demonstrates that rather sophisticated censorship and control is possible at scale. While not currently practiced in the US or Europe, it shows that large social media sites could certainly do it
"This technique has then been used in internet chat rooms by replacing restricted vocabulary. But in particular, on WeChat, this has led to some interesting blocks. For example, recently a recipe for scrambled eggs was blocked and widely circulated as an example of an interesting false positive."
He added that China has developed a range of "sophisticated" censorship technologies to curb opposition to its politics and laws.
Ullrich said: "Although WeChat is almost exclusively used by Chinese users, approximately 10 per cent of its 800 million+ users live outside of China. For these users, Chinese filtering and censorship do not apply.
"This means that users of WeChat in other countries are not affected, even if they are in the same chat room as Chinese users.
"What this means for other countries is that it demonstrates that rather sophisticated censorship and control is possible at scale. While not currently practiced in the US or Europe, it shows that large social media sites could certainly do it."
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago