The Chinese internet company Tencent has shut down 20 million account on its popular messaging app WeChat which were reportedly linked to prostitution. The shutdown was linked to operation "Thunder Strike," according to the Chinese state media.

WeChat, the messaging app, is the most popular one in China and has an active user base larger than the population of the United States, making the 20 million cancelled accounts just 5% of the total. Still, operation “Thunder Strike" is part of a larger government campaign to create clean up the internet.

Operation Thunderstrike was launched last month, specifically targeting WeChat. "Some people are using this platform to disseminate negative or illegal harmful information to the public, seriously damaging the internet system and hurting public interest," Reuters reported, quoting the Chinese state media

The "healthy cyberspace" movement means ridding the Chinese web of "pornography and salacious fan fiction, as well as the American television show 'The Big Bang Theory'," Quartz reported on Tuesday

Quartz describes WeChat as "right at the center" of the shift prostitution has taken in China -- from the streets to the web. Unlike the popular microblogging app Weibo, the Chinese government isn't able to moniter and censor WeChat, which offers private messaging as well as payment services.