Durbin sent the letter to Baidu - China's big search engine. The Senator is concerned about Baidu's censorship of search results and a possible future relationship with Facebook. Why should a U.S. Senator have a say about what a Chinese company is doing? Durbin argues it's because Baidu's shares are traded on the U.S. stock exchange. Durbin is also developing a new Internet freedom bill that would "hold the Chinese search giant and other U.S.-based or U.S.-listed technology companies liable for failing to protect human rights."