Countless terrorist plots have been disrupted by America's massive Prism network of surveillance programmes, according to NSA chief Keith Alexander (pictured, top).
In a US Senate hearing, Alexander defended the Internet and telephone spying initiatives that were revealed by whisteblower Edward Snowden to the international press recently.
"It's dozens of terrorist events that these have helped prevent," Alexander said of the programmes.
Snowden, a former CIA and NSA contract worker, bolted to Hong Kong before leaking the information to the Guardian and Washington Post. He has since vowed to fight extradition.
US officials have admitted that the programmes exist, and President Barack Obama has said that Prism was closely overseen by both Congress and America's legal system. US Secretary of State John Kerry has also spoken out, commenting: "With respect to privacy, freedom and the Constitution, I think over time this will withstand scrutiny and people will understand it."
The programmes, Kerry added, had prevented some "pretty terrible events." For their part, American intelligence officials have insisted that agents do not listen in to citizens' telephone conversations and have defended the programmes as vital national security tools.
Alexander added that intelligence officials were "trying to be transparent" about the programmes; however, the NSA boss said that details would be withheld "because if we tell the terrorists every way that we're going to track them, they will get through and Americans will die."
Whatever the case, it now seems certain that your Internet conversations are no longer as secure as you thought - an inconvenient truth we first highlighted over a year ago.
In May 2012, we reported that the Obama administration was creating a new agency to spy on your Skype.