Google has expressed outrage following a report that America's National Security Agency has hacked its data links, saying it is not aware of such activity but there is an urgent need for reform.
The comments follow a Washington Post report based on leaks from ex-US intelligence contractor Edward Snowden claiming that the NSA hacked links connecting data centres operated by Google and Yahoo.
The agency's director, General Keith Alexander, told Bloomberg TV it is not authorised to go into a US company's servers and take data.
However, this is not a direct denial of the latest claims, the BBC reports.
The revelations stem from documents leaked by Mr Snowden, who has been granted temporary asylum in Russia and is wanted in the United States in connection with the unauthorised disclosures.
The documents say millions of records were gleaned daily from the internet giants' internal networks.
They suggest that the NSA intercepted the data at some point as it flowed through fibre-optic cables and other network equipment connecting the companies' data centres, rather than targeting the servers themselves. The data was intercepted outside the US, the documents imply.
Meanwhile, the United Nations says it has received assurances from US authorities that American intelligence agencies are not spying on the UN's internal communications, and will not do so in the future.
The pledge follows a report in the German news magazine Der Spiegel that the US National Security Agency had gained access to UN video-conferencing systems. There has been no comment from the US officials.