Barack Obama's new privacy watchdog has delivered its first bark, with a letter to intelligence chiefs urging them draft stronger rules on domestic surveillance, something it revealed had not been updated for 30 years.

The intervention of the Privacy and Civil Liberties Oversight Board, its first since the appointment of new staff by the White House earlier this year, came as Obama acknowledged that technology was outpacing the checks put in place to protect privacy and said the National Security Agency was "scary to people".

"I think there are legitimate concerns that people have that technology is moving so quick that, you know, at some point, does the technology outpace the laws that are in place and the protections that are in place?," said the president in a CNN interview that aired on Friday. "Do some of these systems end up being like a loaded gun out there that somebody at some future point could abuse?"

Hours earlier, the Privacy and Civil Liberties Oversight Board (PCLOB) wrote to director of national intelligence James Clapper and the Department of Justice calling for them to begin formulating new guidelines to reflect recent advancements in surveillance capabilities.

It said the board had "learned that key procedures that form the guidelines to protect 'information concerning United States persons' have not comprehensively been updated, in some cases in almost three decades, despite dramatic changes in information use and technology".

PLCOB also requested that "both the attorney general and the director of national intelligence work together to focus the attention necessary to update each element of the intelligence community's procedures to collect retain and disseminate US persons' information".

It said procedures should capture "both the evolution of technology and the roles and capabilities of the intelligence community since 9/11".

"Specifically, the board would appreciate receiving by October 31, 2013, an agency-by-agency schedule establishing a time frame for updating each agency's guidelines," added chairman David Medine.

"In the meantime, the board would appreciate a briefing on the status of the guidelines and process for reviewing and updating them."

Previously PCLOB has been criticised for being too close to the administration and failing to address growing threats to privacy, but its new-found teeth appear to co-incide with a shift in tone from the White House.

In his CNN interview Obama said: "What's been clear since the disclosures that were made by Mr Snowden is that people don't have enough information and aren't confident enough that, between all the safeguards and checks that we put in place within the executive branch, and the federal court oversight that takes place on the program, and congressional oversight, people are still concerned as to whether their emails are being read or their phone calls are being listened to."

"I recognise that we're going to have to continue to improve the safeguards and, as technology moves forward, that means that we may be able to build technologies that give people more assurance, and we do have to do a better job of giving people confidence in how these programs work."

The president hinted at a series of concessions and reforms likely to take place in the coming weeks as Congress returns and responds further to the revelations of sweeping surveillance powers triggered by the Snowden leaks.

"I am open to working with Congress to figure out, can we get more transparency in terms of how the oversight court works? Can – do we need a public advocate in there who people have confidence in?" Obama said.

"There's no doubt that, for all the work that's been done to protect the American people's privacy, the capabilities of the NSA are scary to people."