The NSA is the best hidden of all the US intelligence services – and its secrecy has deepened as its reach has expanded.

The very existence of National Security Agency (NSA) was not revealed for more than two decades after its establishment in 1952, and even now its structure and activities remain largely unknown. Hence its wry nickname: No Such Agency.

Of all the US intelligence services, it is has been the best hidden, and has prided itself on having the fewest leaks – at least until now. How many people does it employ? That is classified. Just how many people does it target? The NSA tells members of Congress that it does not have the tools to provide such figures.

When Harry Truman set up the NSA, it was exclusively aimed at monitoring communications abroad. The question that had exercised politicians and civil rights organisations since the Senate unveiled it in 1975 is to what extent its ferocious appetite for data has encompassed American citizens.

As technology has evolved, so has the NSA’s capacity to intercept an astonishing variety and volume of communications. Satellites scoop up calls and emails in the ether and beam the information back to earthbound receiving stations.

In the years since 9/11, as the role of the NSA has snowballed, so has the debate over its operations. In 2005, the New York Times reported that the Bush administration had secretly authorised the NSA to eavesdrop on Americans and others inside the US, to search for terrorist activity without the Fisa court warrants. The massive surveillance programme has continued under the Obama administration, at home as well as abroad. And the culture of intense secrecy persists. For years, Senators Ron Wyden and Mark Udall have been demanding to know just how many people inside the US have been spied on by the NSA. No answer has been forthcoming.

Full article: Gaurdian UK