United States President Barack Obama has defended sweeping government surveillance of Americans' phone and internet activity, calling it a modest encroachment on privacy that is necessary to defend the US from attack.
During a visit to California's Silicon Valley, Mr Obama emphasized that the programmes are supervised by federal judges and authorized by Congress.
"Nobody is listening to your telephone calls. That's not what this programme is about," he said.
The comments are a response to revelations in two newspapers that agencies have been monitoring telephone and internet activities far beyond what had been made public.
That has launched a broad debate about the proper limits of government surveillance in the aftermath of the September 11, 2001 terror attacks.
Mr Obama acknowledged having "a healthy skepticism" about the programmes before he was first elected in 2008, but said he had since come to the conclusion that such "modest encroachments on privacy" were worth it, Reuters reports.
He says people can't have 100% security, then also have 100% privacy and zero inconvenience.
Meanwhile, the bosses of internet companies Google and Facebook have denied that their firms have taken part in the surveillance programme.
