A senior US senator wrote a letter to Baidu (BIDU.NASDAQ) founder Robin Li this week, expressing his concern that Baidu doesn’t protect its users’ freedom of expression and privacy, the Wall Street Journal reported. The letter came after rumors circulated that the Chinese search giant was in talks with Facebook for a potential partnership. US Senator Richard Durbin, a Democrat from Illinois, said in the letter that he is working on legislation which would hold US-based or US-listed technology companies liable for failing to protect human rights. The senator is “drafting an internet freedom bill” that would encourage tech companies to adopt appropriate policies and practices to protect human rights by giving them safe harbor from liability, said Durbin’s spokesman Max Gleischman. “Companies that fail to adopt such policies could be held liable if their products or services are involved in serious human rights violation that was reasonably foreseeable.”