The US National Security Agency (NSA) now has the legal right to monitor over a third of the world's telecoms traffic.

Under new provisions of the Protect America Act 2007 recently signed into legislation, as an amendment to the Foreign Intelligence Surveillance Act (FISA) of 1978, the NSA can monitor all traffic originating, passing through or terminating in the US without requiring a court order.

According to telecoms analysts, in excess of 35 per cent of the world's voice and non-voice telecoms traffic is routed through US hubs.

The bill was hotly debated in the US House of Representatives with right-leaning congressional proponents saying the amendment is necessary in the ongoing war on terrorism, and left-leaning representatives arguing that it would undermine civil liberties.

"In the 30 years since Congress enacted the Foreign Intelligence Surveillance Act, telecommunications technology has dramatically changed," said congressman Lamar Smith, representing the 21st district of Texas.

"As a result, the intelligence community is hampered in gathering essential information about terrorists needed to prevent attacks against America. Congress must modernise FISA to address this problem."

"This bill goes far beyond what is necessary and … would grant the Attorney General the ability to wiretap anybody, anyplace, anytime, without court review, without any checks and balances," argued congresswoman Zoe Lofgren, representing the 16th district of California.

"I think that this unwarranted, unprecedented measure would simply eviscerate the fourth amendment that protects the privacy not of terrorists, but of Americans."

"Some people have some confusion, I think, over civil rights versus rights in a time of war …[and] we are in a war," said Congressman Louie Gohmert, representing the 1st district of Texas.

"This is not a bill that will allow surveilling American citizens on American soils. But the message is this: If you declare war on this country and you are a foreigner, we may just listen in on your conversations."

The bill was passed by 44 votes with 23 abstentions.