50 popular Chinese writers are accusing China's largest search engine -- Baidu of copyright infringement. In their claims against the company, they brand Baidu's behavior as a "thief" and hope the company will solve the problem.

Dozens of Chinese writers, including popular blogger Han Han and well-known writer Jia Pingwa signed a letter claiming Baidu provided their works for free to download on its online library Baidu Wenku. They claim Baidu did this without their permission.

Baidu Wenku was launched in 2009, and allows users to read, share and download files and books for free. Readers can also purchase books from their online library - but at a much lower price.

All documents are uploaded by online users. As of November 2010, Baidu Wenku stockpiled more than 10 million files and books. That accounts for 70 percent of China's online file-sharing market.

In reference to the accusation, Baidu's spokesman Kaiser Kuo say the search engine "attaches great importance to intellectual property rights protection" and deleted "tens of thousands of infringing items" uploaded by users.

In a disclaimer on its website, Baidu says users who uploaded the files must accept all liabilities and be responsible for compensation in any copyright disputes.

But the writers insist Baidu should bear the responsibility, claiming the company took advantage of the uploads to "enhance its own influence, boost its stock price and increase profits".

The firestorm is also spreading to online bookstores. Dangdang.com, one of China's largest online booksellers, will stop advertising on Baidu starting April first.