The assumption is all countries spy on each other, but only one country has an eavesdropping nuclear weapon

German Chancellor Angela Merkel is angry and outraged by news the US has been monitoring her cell phone calls.

Merkel joins a long list of other world leaders upset over the spying prowess of the National Security Agency. 

But is all that anger real? The assumption is that all foreign countries spy on one another.

To answer this question, we bring in James Bamford. He's the author of "Body of Secrets: Anatomy of the Ultra-Secret National Security Agency."

Coincidentally, Bamford is in Berlin right now. And he says that, yes, the anger is real. It comes down to the sheer size and capability of the NSA spying network. 

"The US has the equivalent of an eavesdropping nuclear weapon, while the other countries have the equivalent of an eavesdropping Howitzer." 

That nuclear weapon is the NSA. But the problems with utilizing such a massive system of data collection and snooping is that you get too much data on too many targets. In effect, you create your own haystack where needles can and will hide.

Documents leaked by Edward Snowden show that little to no useful information has come from spying on the 35 leaders.

Other than angering its allies.