A leaked 2006 memo from the NSA to staffers in the White House, State and the Pentagon asked them to search their rolodexes for the personal numbers of world leaders so the Agency could spy on them. At least 35 world leaders were subsequently wiretapped by the NSA.
The memo, dated October 2006 and which was issued to staff in the agency's Signals Intelligence Directorate (SID), was titled "Customers Can Help SID Obtain Targetable Phone Numbers".
It begins by setting out an example of how US officials who mixed with world leaders and politicians could help agency surveillance.
"In one recent case," the memo notes, "a US official provided NSA with 200 phone numbers to 35 world leaders … Despite the fact that the majority is probably available via open source, the PCs [intelligence production centers] have noted 43 previously unknown phone numbers. These numbers plus several others have been tasked."
The document continues by saying the new phone numbers had helped the agency discover still more new contact details to add to their monitoring: "These numbers have provided lead information to other numbers that have subsequently been tasked."
But the memo acknowledges that eavesdropping on the numbers had produced "little reportable intelligence". In the wake of the Merkel row, the US is facing growing international criticism that any intelligence benefit from spying on friendly governments is far outweighed by the potential diplomatic damage.
NSA monitored calls of 35 world leaders after US official handed over contacts [James Ball/The Guardian]