US technology companies on Monday called on President Barack Obama and members of Congress to limit surveillance of citizens.

Companies, including Apple, Facebook and Google, called on US leaders to set an example for countries worldwide in the wake of revelations of broad surveillance by the National Security Agency that have prompted an outcry from many US allies and civil libertarians.

"We understand that governments have a duty to protect their citizens. But this summer`s revelations highlighted the urgent need to reform government surveillance practices worldwide," they wrote.

"The balance in many countries has tipped too far in favor of the state and away from the rights of the individual rights that are enshrined in our Constitution. This undermines the freedoms we all cherish. It`s time for change."

The internet firms lay out five principles for global reforms of state surveillance on a joint website.

They call for an end to mass gathering of communication data from the internet, noting governments should limit such efforts to specific suspects.

Responsible authorities and courts should be more tightly controlled, they argue. The companies, which also include Microsoft, Twitter, AOL, Yahoo and LinkedIn, also seek to be allowed to publicize how often and why governments seek user information.

The campaign calls for the free flow of information online, including over international borders, and calls for governments to establish an international framework to govern requests for data across different jurisdictions.

The offensive follows months of revelations about surveillance by the NSA, including spying on emails and the gathering of data from internal connections between data centres at Google and Yahoo.

The companies also hope to protect their business models from a loss of trust that could damage their email, search, chat and other services. "

People won`t use technology they don`t trust," Microsoft general counsel and executive vice president Brad Smith said.

"Governments have put this trust at risk, and governments need to help restore it."

BdST 2159 HRS, DEC 9, 2013