The Guardian and the Washington Post both have published new disclosures about the Prism program, under which the National Security Agency snoops on Americans' online activities.
Kurt Upsahl, senior staff attorney for the Electronic Frontier Foundation, said the digital civil rights organization "has been saying for some time that there has been a warrantless surveillance program going on" for the collection of electronic content.
"It allegedly has the cooperation of nine very prominent Internet companies, from which we're seeing a slew of denials," he told NBC News. "Denials that are designed to leave the impression that the companies are not participating."
At "minimum," he said, "Congress should start holding some hearings and get to the bottom of what's going on."
The American Civil Liberties Union was also quick to offer its concerns about what was reportedly a court-approved program that had the consent of Congress.
"These revelations are a reminder that Congress has given the government far too much power to invade individual privacy, that existing civil liberties safeguards are grossly inadequate," Jameel Jaffer, the ACLU's deputy legal director, said in a statement, adding that "powers exercised entirely in secret, without public accountability of any kind, will certainly be abused.”