In a letter sent to the Justice Department, Google has asked the government for permission to expand the information it publicly discloses about the national security requests it receives.

Google has asked Attorney General Eric Holder and FBI Director Robert Mueller for permission to publish information about the number of requests for data it gets under the Foreign Intelligence Surveillance Act.

The company made the request to help address public concerns that Google might be providing unfettered access to user data.

"[G]overnment nondisclosure obligations regarding the number of FISA national security requests that Google receives, as well as the number of accounts covered by those requests, fuel that speculation," Google's Chief Legal Officer David Drummond in the letter, published to Google's blog.

"We therefore ask you to help make it possible for Google to publish in our Transparency Report aggregate numbers of national security requests, including FISA disclosures—in terms of both the number we receive and their scope," he continued. "Google’s numbers would clearly show that our compliance with these requests falls far short of the claims being made. Google has nothing to hide."

The unprecedented public plea comes in the wake of leaks by a former NSA contractor describing a data collation system the FBI and NSA use to obtain documents from internet companies like Google, Yahoo and Facebook. The program, called PRISM, led to speculation about the extent of the requests and the number of people being spied on, which put Google and other companies under pressure to assure customers that they don't provide direct access to user data, but only respond to court ordered requests that are targeted.

Under FISA, the government can seek data and communications that belong to persons outside the U.S. or communications that occur between a U.S. person and someone outside the U.S.

Stories about PRISM, published by the Guardian and Washington Post, shone a light on the massive amounts of data the government collects from companies under FISA each year but did not provide information about the extent of the requests.

Google is not allowed to disclose publicly the number of requests it gets for data under section 702 of the FISA act and was only able to make the public request for more transparency because the Director of National Intelligence acknowledged last week the existence of PRISM and the fact that service providers like Google have received Foreign Intelligence Surveillance Act (FISA) requests.

For the first time this year Google began publishing information about the National Security Letters it receives each year after negotiating with the government for permission to disclose them. The NSL figures Google provides are broadstroke numbers in the form of a range, such as 0-999 requests, and don't provide a clear picture of the extent to which the government requests data from Google. But civil liberties activists commended Google at the time for the first step while pushing Google to provide more information. Google pointed to that recent disclosure of NSL numbers as further reason to allow it to disclose FISA numbers as well.

"There have been no adverse consequences arising from their publication, and in fact more companies are receiving your approval to do so as a result of Google’s initiative," Drummond wrote in his request. "Transparency here will likewise serve the public interest without harming national security."

Google published the data on National Security Letters after a lengthy negotiation with the government to obtain permission to do so.

Google CEO Eric Schmidt, speaking to MSNBC's Rachel Maddow in 2008 said the company is constrained in what it can do about the government data requests it gets under court order. Short of pushing back on orders that Google considers too broad, there's little else it can do.

"We are required to follow U.S. law and we do so even if we don't like it," Schmidt said. "And as the CEO of a public company or even a private company there can be no other answer."