China’s top search engine operator Baidu has come under fire for suddenly deleting all posts and comments made before 2017 on Tieba, a massive online community.

Baidu announced on May 14 that all posts on Tieba made before January 1, 2017, would be hidden due to a system upgrade and maintenance, sina.com.cn reported.

Users are no longer able to view and search the posts made before 2017 on respective discussion groups.

The IT giant did not disclose when people would be able to see the posts again or the old system would resume.

Chinese users, including media outlets, slammed the company for its move without giving notice, as many original works created by users were posted on the forums.

But this is not the first time that the company has closed discussion groups without notice.

Baidu Tieba, or Post Bar, launched in 2003 with about 22 million discussion groups ranging from food to films to foreign affairs. Its registered users reached 1.5 billion.

The company also came under fire in 2016 after it capitalized on its disease-theme forums, as users revealed that online communities had been flooded with advertisements for unlicensed hospitals.