Google, Microsoft and Yahoo have signed up to a set of voluntary guidelines that are designed to reduce the risk that their actions lead to human rights abuses in China and other countries. The principles, written in conjunction with two human rights groups, are a reaction to the fierce public criticism that all three faced two years ago for bowing to various degrees to Chinese internet controls.

The guidelines call for internet and communication companies to comply with censorship and other strictures only when they have received a formal legal request. Beijing currently bases its censorship regime on vaguely worded regulations that encourage local internet companies to be conservative in their self-censorship and leave officials with wide latitude to punish companies and individuals who fail to fall in line.