SHANGHAI — One man spent 15 days in a detention center. The police threatened another’s family. A third was chained to a chair for eight hours of interrogation.
Their offense: posting on Twitter.
The Chinese police, in a sharp escalation of the country’s online censorship efforts, are questioning and detaining a growing number of Twitter users even though the social media platform is blocked in China and the vast majority of people in the country cannot see it.
The crackdown is the latest front in President Xi Jinping’s campaign to suppress internet activity. In effect, the authorities are extending their control over Chinese citizens’ online lives, even if what they post is unlikely to be seen in the country.
“If we give up Twitter, we are losing one of our last places to speak,” said Wang Aizhong, a human-rights activist who said the police had told him to delete messages criticizing the Chinese government.
When Beijing is unable to get activists to delete tweets, others will sometimes do the job. Mr. Wang refused to take down his tweets. Then, one night last month while he was reading a book, his phone buzzed with text messages from Twitter that contained backup codes to his account.
An hour later, he said, 3,000 of his tweets had been deleted. He blamed government-affiliated hackers, although those who were responsible and the methods they used could not be independently confirmed.
