Reports of sweeping government surveillance of phone and Internet activity put the Obama administration on the defensive Friday, adding pressure on President Barack Obama to explain why such tactics are necessary.
The Washington Post reported late Thursday that federal authorities have been tapping into the central servers of companies including Google, Apple and Facebook to gain access to emails, photos and other files, allowing analysts to track a person's movements and contacts.
That added to privacy concerns sparked by a report in Britain's Guardian newspaper that the National Security Agency had been mining phone records from millions of customers of a Verizon Communications subsidiary.
Obama, who pledged to run the most transparent administration in U.S. history, did not mention the surveillance furor in two meetings with supporters on Thursday evening.
He may be forced to broach the subject during his meetings with Chinese President Xi Jinping at a California summit on Friday, in which U.S. concerns about alleged Chinese hacking of American secrets were expected to be high on the agenda.
Members of Congress are routinely briefed by the NSA on secret surveillance programs, but it is not yet clear how much they knew about the widespread surveillance of private Internet activity reported by the Washington Post.
Rep. Henry Waxman, a California Democrat, said on Friday he thought the administration had good intentions but stressed the program was "just too broad an over-reach."
"I think there ought to be some connection to suspicion, otherwise we can say that any intrusion on all of our privacy is justified for the times that we will catch the few terrorists," Waxman told MSNBC. "Good intentions are not enough. We need protections against government intrusion that goes too far."
PRISM surveillance program
The Washington Post said the surveillance program involving firms including Microsoft, Skype and YouTube, code-named PRISM and established under Republican President George W. Bush in 2007, had seen "exponential growth" under the Democratic Obama administration.
It said the NSA increasingly relies on PRISM as a source of raw material for its intelligence reports.
James Clapper, the director of national intelligence, said the report contained "numerous inaccuracies," and some of the companies identified by the Washington Post denied that the NSA and Federal Bureau of Investigations (FBI) had "direct access" to their central servers.
Microsoft said it does not voluntarily participate in government data collection and only complies "with orders for requests about specific accounts or identifiers.
Erwin Chemerinsky, a law professor at the University of California Irvine, said the program was "deeply disturbing" and went beyond what was constitutionally acceptable.
"It is a huge gathering of information by the federal government. The argument that it protects national security is unpersuasive," he said.
The White House sought on Thursday to defend the National Security Agency's secret collection of telephone records from millions of Americans as a "critical tool" to prevent attacks. National Intelligence Director James Clapper said the data was only used in specific investigations of non-U.S. citizens.