China's Ministry of Public Security(MPS) has closed 1,100 self-media accounts and 31 websites suspected of engaging in trolling and extortion since the start of the year.

The ministry said that it cracked down on 28 cases involving online trolling and ghostwriters hired to post slanderous content, and arrested 67 people.

More than 80 enterprises and organizations were blackmailed.

Claiming "legal and social supervision," some suspects organized large-scale operations in paid comments or posts on social media platforms such as Sina Weibo and WeChat, which have about 400 million and 1 billion active users per month, respectively, China Central Television (CCTV) reported.

They also provided services, including paid public activities and deletion of online content, to manipulate public opinion.

In a statement, the MPS accused the suspects of engaging in extortion, fraud, running illegal businesses, causing trouble, libel, and violating personal information, Xinhua reported.

Some suspects have been sentenced to jail time, others are awaiting trial, and the rest are being investigated.

Zhu Wei, a professor at the China University of Political Science and Law, said it was a good start to normalize legal regulation of activities in cyberspace.

Such operations have been a cancer that has seriously violated net users' right to knowledge and merchants' legitimate management, Zhu told the Global Times.

Service purchasers who promote the black-market chain should also be punished. Chinese authorities, including law enforcement departments and market regulation administrations, should jointly act to fight similar cyber crimes, Zhu said.

The Cyberspace Administration of China (CAC), the country's cyber authority, has vowed a thorough clean-up of self-media that publishes rumor-based and malicious content.

It had shut down or punished more than 9,800 self-media accounts in a campaign that began in late October.

The CAC met with media platforms, including Baidu, Tencent, Sina and Jinri Toutiao, and urged them to seriously regulate self-media on their platforms.