Bilibili, one of the most popular Chinese video-sharing sites, has taken a large number of mostly foreign TV shows and movies offline since Wednesday.

Its millions of young users were left speculating, until the website on Thursday evening sent out a statement saying it was in the process of reviewing some of its content. “During the review period, some movies and TV shows might be inaccessible,” it said, adding that content found to violate regulations would be removed. The statement did not specify a reason or a time frame.

Previously, netizens had suggested that copyright issues might be to blame. Much of the videos on Bilibili are user-uploaded, meaning the website potentially violates a 2004 rule requiring websites to obtain permission from copyright holders and media regulators for all of their online TV shows and movies.

A Bilibili public relations employee declined to comment on the disappearances when contacted by Sixth Tone on Thursday.

The move follows increasingly strict regulation of online media. Bilibili had cultivated a reputation as a freewheeling haven for enthusiasts of subcultures such as anime, comics, and games, but on July 5 the website was obliged to implement a real-name registration system for its uploaders in response to China’s new cybersecurity law.

AcFun, another video-sharing platform similar to Bilibili, has also taken recent hits. On June 26, China’s media regulator, the State Administration of Press, Publication, Film, Radio, and Television (SAPPRFT), published a notice demanding AcFun and several other websites shut down their streaming services because they were not licensed to distribute video content online. AcFun suspended its TV and movie channels and removed all content that was found to be in violation of SAPPRFT’s regulations.

Also in June, new guidelines from the industry body for online broadcasting prohibited unpatriotic and vulgar content. The document specifically banned depictions of homosexuality, which it included along with incest and sexual violence in a list of “abnormal sexual behaviors.”

Net users have reacted with disappointment at the removal of the shows and movies. One well-known subtitle group — people who volunteer their time to translate subtitles of foreign-language programming into Chinese — told its followers on their Weibo microblog that they should go back to downloading TV shows, as was common 10 years ago.

Another Weibo comment lamented the disappearance of videos from A Station and B Station — the nicknames of AcFun and Bilibili respectively. “Now, C Station rules the world” the comment continued, linking to China’s state-controlled broadcaster CCTV.

This article has been updated to include Bilibili’s statement.

Editor: Kevin Schoenmakers.

(Header image: A young woman wears a paper bag displaying the logo of Bilibili, a popular Chinese video-sharing website, during a basketball game in Shanghai, Nov. 11, 2016. IC)