President Barack Obama delivered a passionate defense on Friday of National Security Agency (NSA) programs that secretly acquire information about Americans’ phone calls, saying criticism of them is all “hype”.

“My assessment and my team’s assessment was that [the programs] help us prevent terrorist attacks and that the modest encroachments on privacy that are involved in getting phone numbers or duration [of calls] without a name attached… It was worth us doing.”

Barack Obama made the remarks at a press conference in response to revelations about two separate programs used to spy on American citizens and foreign nationals. One program involves the collection of U.S. Verizon customers phone records. The other program – dubbed PRISM – allows the government to scour the Internet usage of foreign nationals overseas who use any of nine U.S.-based internet providers such as Microsoft and Google.

“I think it’s important to understand that you can’t have 100% security and then have 100% privacy and zero inconvenience,” the president said.

“We’re going to have to make some choices as a society.”

Barack Obama said the PRISM program does not involve monitoring the email content of U.S. citizens or anyone living in the U.S., and he repeatedly stated that both programs – the phone spying and PRISM – have been approved by Congress.

“You can complain about <<big brother>> and how this is a potential program run amuck,” Barack Obama added.

“But when you actually look at the details, then I think we’ve stuck the right balance.”

Barack Obama said the programs have plenty of checks in place, including repeated authorizations by Congress and approval by the Foreign Surveillance Intelligence Court, to assure no abuses by the government.

“Nobody is listening to your telephone calls,” he said.

“That’s not what this program’s about.”

If U.S. citizens decide they want to axe the programs, Barack Obama “welcomes” that debate, he said. But at the same time, he expressed concern over the fact that the classified programs were leaked to the media.

“I don’t welcome leaks, because there’s a reason why these programs are classified,” the president said.

The Washington Post reported Friday that for the past six years, U.S. intelligence agencies have been extracting audio, video, photos, e-mails, documents and other information to track people’s movements and contacts.

The Silicon Valley companies involved in the PRISM program are Apple, Facebook, Microsoft, Google, Yahoo, YouTube, Skype, AOL and the lesser known Internet company PalTalk, which has hosted a lot of traffic during the Arab Spring and the on-going Syrian civil war.

The scandal deepened after it emerged that the Silicon Valley Internet giants have been passing the acquired information on to the UK.

The Guardian reported that GCHQ, the UK’s communications intelligence agency, has had access to data collected through PRISM program since at least June 2010, and last year generated 197 intelligence reports from it.

The newspaper also first reported the phone-spying program, through which the NSA has been collecting information on Verizon customers’ phone calls, including call duration and frequency.

The revelations – which are the largest anti-terror intelligence-gathering operation since 9/11 – have placed massive pressure on Barack Obama, who is already reeling from the recent IRS scandal.

In addition to the names already on the list, the cloud-storage service Dropbox was described as “coming soon” to PRISM.

Twitter, which is known for zealously protecting its users’ privacy, is conspicuous in its absence from the list of Internet companies involved in the data-mining program.

PRISM was launched in 2007 with the blessing of special federal judges under the Foreign Intelligence Surveillance Act. The Post said that several members of the U.S. Congress were made aware of the classified data-gathering program, but were sworn to secrecy.

All forms of wiretapping of U.S. citizens by the NSA requires a warrant from a three-judge court set up under the Foreign Intelligence Surveillance Act passed in 1978.

But former President George W. Bush issued an executive order shortly after the September 11, 2001, attacks in New York that authorized the NSA to monitor certain phone calls without permission.

The warrantless wiretapping program remained a secret until 2005, when a whistleblower went to the press to reveal the extent of the surveillance.

And although the NSA has strenuously denied acting beyond its surveillance powers, groups such as the American Civil Liberties Union (ACLU) have warned that the Cyber Intelligence Sharing and Protection Act (CISPA) – a bill currently passing through Congress – could dramatically increase the amount of personal data that government agencies have legal access to.

The particulars of today’s revelation were outlined in a top-secret PowerPoint presentation for senior intelligence analysts, which ended up being leaked to The Post and UK’s The Guardian.

According to The Washington Post, the tech companies are knowingly taking part in PRISM, but The Guardian reported than all nine pleaded ignorance of the program.

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