Authorities in the southern Chinese province of Guangdong have formally arrested a man for "insulting" the country's president on social media platform WhatsApp, claiming to have had access to a "backdoor" in the encrypted app.
Zhang Guanghong, a rights activist from the provincial capital Guangzhou, was formally arrested for retweeting a post about President Xi Jinping, his lawyer told RFA on Friday.
Zhang was initially detained by cybersecurity police in his home district of Yuexiu in early October, ahead of the ruling Chinese Communist Party's 19th national congress.
His lawyer Sui Muqing, who visited Zhang in the Yuexiu Detention Center on Thursday, said his client is accused of "using communications technology platform WhatsApp to retweet a post that insulted Chinese President Xi Jinping."
"Allegedly, they were able to use a backdoor in the app to get the evidence they needed," Sui said. "But regardless of how they obtained it, I suspect it involved a violation of people's privacy."
He said police are basing their case on a single item reposted by Zhang.
"He told me that the post the police showed him had nothing insulting in it at all," he said. "It had some critical remarks about Xi Jinping, calling him militaristic, but this was just a comment, and yet they have arrested him for it."
"To me, it beggars belief, that controls on public expression should be so strict," Sui said.
According to Sui, cases of "insult" are usually brought by the person who feels insulted, except in cases involving national leaders, where "serious public harm" has been done, in which case the state may bring a prosecution.
"In a civilized society, it's perfectly normal to see all kinds of invective hurled at national leaders," he said. "A civilized society ought to allow people to use sharp criticism."
But a technology expert in Guangzhou said there should be no such thing as a "backdoor" into WhatsApp, and that the Chinese police would have no access to the source code.
"I think they are just trying to protect their own agents by saying this," the expert said. "It's more likely that there are people in the WhatsApp group chat who are spying for the police."
"They probably send screenshots of each day's chat to the police, and that's what they used to arrest Zhang Guanghong," he said. "But the thing he retweeted is just an excuse: The police probably wanted to go after him anyway."
Reported by Yang Fan and Qiao Long for RFA's Mandarin Service and by Wong Lok-to for the Cantonese Service. Translated and edited by Luisetta Mudie.