I imagine that NSA’s success at spying on Felipe Calderón’s inner circle made it a lot easier for the US to convince him to allow “near-complete entree to Mexico’s territory and the secrets of its citizens” in the name of the war on drugs.

A report classified as “top secret” said: “TAO successfully exploited a key mail server in the Mexican Presidencia domain within the Mexican Presidential network to gain first-ever access to President Felipe Calderon’s public email account.”

I presume continued spying on Enrique Peña Nieto has convinced him to permit that access to largely remain in place, in spite of his campaign promises.

But one of the most interesting aspects of the Spiegel story outlining such spying is the description of how metadata relates to content. In 2012, the NSA conducted analysis of Peña Nieto’s metadata, along with that of 8 of his associates, to figure out who to wiretap.

For two weeks in the early summer of 2012, the NSA unit responsible for monitoring the Mexican government analyzed data that included the cell phone communications of Peña Nieto and “nine of his close associates,” as an internal presentation from June 2012 shows. Analysts used software to connect this data into a network, shown in a graphic that resembles a swarm of bees. The software then filtered out Peña Nieto’s most relevant contacts and entered them into a databank called “DishFire.” From then on, these individuals’ cell phones were singled out for surveillance.

According to the internal documents, this led to the agency intercepting 85,489 text messages, some sent by Peña Nieto himself and some by his associates. This technology “might find a needle in a haystack,” the analysts noted, adding that it could do so “in a repeatable and efficient way.”

That is, at least in this case, NSA used metadata analysis to find the content that might be most interesting. It’s not entirely sure what “needles” the NSA imagined Peña Nieto had in his haystack (always this metaphor!), but Spiegel describes that US prioritizes collection on the drug war over issues — like human rights and economic development — that might combat the underlying conditions that allow drug trafficking to flourish.

In the case of Mexico, the US is interested primarily in the drug trade (priority level 1) and the country’s leadership (level 3). Other areas flagged for surveillance include Mexico’s economic stability, military capabilities, human rights and international trade relations (all ranked at level 3), as well as counterespionage (level 4).

This metadata to content relationship is not surprising in the least. But it implies a faith — and I do mean “faith” — in data analysis that might not be sound.

Not to mention, when transplanted into the United States, a suspect basis for probable cause.