Microsoft, Google, and two other technology companies will develop a code of conduct with a coalition of nongovernmental organizations (NGOs) to promote freedom of expression and privacy rights, they announced Friday.

The two companies along with Yahoo, and Vodafone Group said the new guidelines are the result of talks with Business for Social Responsibility (BSR) and the Berkman Center for Internet & Society at Harvard Law School.

Technology companies have come under fire for providing equipment or software that permits governments to censor information or monitor the online or offline activities of their citizens. For example, last year, Google's approach to the China market was criticized over its creation of a censored, local version of its search engine.

A Yahoo subsidiary was cited by human rights groups for working with Chinese police to identify political activists, who were ultimately arrested and prosecuted for posting anti-government opinions and information online.

The parties involved said that would a framework that would hold signatories accountable for their actions in the areas of freedom of expression and privacy rights.

The groups participating in development of the guidelines include: Berkman Center for Internet & Society at Harvard Law School; Business for Social Responsibility; Electronic Frontier Foundation; Human Rights Watch; and Reporters Without Borders.