One of China’s most popular travel websites filed a defamation lawsuit on Monday amid allegations that it copied millions of user comments displayed on its platform from some of its closest competitors, calling the now-viral report a “verifiably organized attack.”

On Saturday, Xiaosheng Bibi, a news-related public account on social app WeChat, published an article claiming that some 18 million reviews on Mafengwo, a Chinese travel platform comparable to TripAdvisor, were “pure plagiarism,” having been copied verbatim from other websites — sometimes with the names of those websites still included in them.

Hooray Data, a Chinese data analysis startup that co-authored the report, said it detected at least 7,454 fake accounts on Mafengwo contributing 5.7 million and 12.2 million plagiarized restaurant and hotel reviews, respectively. Hooray Data estimated that 85 percent of the supposedly “real user-generated content” on Mafengwo had been copied from other sites. Four accounts in particular were said to have contributed a combined 11,521 plagiarized reviews.

“They [Mafengwo] used bots to copy 18 million reviews from their rivals,” the article said.

Hours later, Mafengwo responded to Xiaosheng Bibi’s allegation that the travel site was behind the copied content. “The report severely mispresented the facts by attributing [netizens’] illegal acts to the platform itself,” it said in a statement. The company added that bots and fake users accounted for a small proportion of the total users on its platform, and on Monday evening said it had filed a defamation suit.

Neither the Xiaosheng Bibi WeChat account nor Mafengwo’s PR department responded to Sixth Tone’s interview requests by time of publication.

Most of the allegedly plagiarized content came from platforms like group-buying app Meituan-Dianping or travel sites Ctrip and eLong. Other posts seem to have been lifted from English-language platforms like Yelp and Agoda and then put through an online translator. According to the article, one user comment read: “Translated by the Concise English-Chinese Dictionary, we ate two hamburgers today.”

In its statement, Mafengwo stressed that its core services are travelogues, recommendations, and FAQs, not restaurant and accommodation reviews, which it said account for less than 3 percent of its online content. But in a follow-up post on Sunday, Xiaosheng Bibi said that even these “core services” had been targeted by plagiarists: Several of the most-read travelogues on Mafengwo, for example, appeared to be sexualized adaptations of posts from other platforms. Xiaosheng Bibi noted that one especially erotic story on Mafengwo titled “Little Lolita and the Old Man’s Sexy Honeymoon Trip to Sanya” — deleted but still cached — bore an uncanny resemblance to a similar but less licentious post on Ctrip.

Fengma, a user cited in Xiaosheng Bibi’s first article, said he was so annoyed by the bountiful bots commenting under his blog posts that he felt discouraged from posting. When contacted by Sixth Tone, Fengma confirmed his comments but admitted that bots are somewhat common on such large platforms.

According to its website, Mafengwo has more than 100 million users who have traveled to over 200 countries and regions. The company in August hoped to complete a $300 million funding round expected to raise its valuation to between $2 billion and $2.5 billion, according to Reuters.

But Xiaosheng Bibi’s viral article could cause the company’s lofty valuation expectation to take a hit. “If true, Mafengwo’s long-touted tale of ‘professional user-generated content’ would collapse, and its value sink to around 2 billion yuan [$290 million],” Liu Xingliang, president of tech consultancy China Internet Data Center, said in an interview published Monday by financial news outlet Eastmoney.

Introduced in August, the most recent iteration of China’s e-commerce law prohibits false advertising, stating that vendors must honestly describe the goods and services they provide.

Editor: David Paulk.

(Header image: The website of Mafengwo. Duoduo/Sixth Tone)