Google's decision to enlist the help of the National Security Agency in tackling cyber attacks has caused alarm among internet groups and bloggers, who fear that users' personal information could be accessed by the US government.
The Washington Post reported yesterday that the internet giant had turned to the NSA, which conducts surveillance and codebreaking for the federal government, in the wake of a cyber attack it believes came from China.
The agency is responsible for securing the US administration's computer networks against similar breaches, and is said to be helping Google to understand and analyse the attacks.
Sources say that the agreement will not allow the NSA to view users' searches or access email accounts, but the deal has angered some members of the online community.
The Electronic Privacy Information Centre, a public research centre based in Washington, has filed a freedom of information request seeking details of the agency's relationship with Google.
"Google and NSA are entering into a secret agreement that could impact the privacy of millions of users of Google's products and services around the world," the centre's executive director Marc Rotenberg told the New York Times.
Sam Diaz, blogger and senior editor at ZDNet, a technology website, said he felt "squeamish" about the possibility of information sharing between Google and the government, and was sceptical about the NSA's ability to help protect the company's infrastructure.
"I mean no disrespect to my country or my government but I have to ask: Is Washington really the best choice if you're looking for help with something as serious as cyber security?" he wrote.
"After all, I wouldn't exactly place any Washington agency at the cutting edge when it comes to fighting what was referred to as one of the most sophisticated cyber attacks experts had ever seen."
Andrew Beal, writing in Marketing Pilgrim, said: "Big brother just partnered with big brother.
"While it's unlikely that Google's going to hand over any user information, I still don't like how close – and how quickly – Google is snuggling up with perhaps the scariest of all government agencies," he blogged.
Referring to the NSA's monitoring of the email and telephone calls of thousands of Americans after the 2001 terror attacks, Beal wrote: "This is the same agency that tapped your phones and emails without a warrant after 9/11. We're supposed to feel confident it won't take a poke around Google's sensitive data?"
Noah Shachtman, writer of Wired magazine's national security blog Danger Room, described the NSA as a "particularly untrustworthy partner".
"We all know that Google automatically reads our Gmail and scans our Google calendars and dives into our Google searches, all in an attempt to put the most relevant ads in front of us," he wrote.
"But we've tolerated the automated intrusions, because Google's products are so good, and we believed that the company was sincere in its 'don't be evil' mantra."
Shachtman said Google's pledge that its agreement with the NSA would not compromise user data was "hard to believe, given the NSA's track record of getting private enterprises to co-operate, and Google's willingness to take this first step."
The company said it was subject to a "highly sophisticated and targeted attack" in December 2009, which it said originated from China. In January, Google said that it was no longer willing to censor search results on its Chinese service.