US Intelligence agencies hacked into the email of a Mexican president's public email account as part of a systematic, multiyear effort to eavesdrop on government officials “south of the border,” according to the German news magazine Der Spiegel’s analysis of intelligence secrets provided by leaker Edward Snowden.

In 2010, then-president Felipe Calderon’s email was accessed during what was dubbed operation “Flatliquid”.  A top-secret report reveals that the US National Security Agency (NSA) “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.” 

The revelation is likely to upset relations between the United States and Mexico, as similar stories have damaged America’s relations with the second biggest economy in its hemisphere, Brazil.

Previously, it was revealed that the NSA monitored then-presidential candidate Enrique Pena Nieto and others around him in the summer of 2012.  At the time, he summoned the US Ambassador and called for an investigation.  But hacking a President, as opposed to a presidential candidate, raises the bar, and the world will be watching Mexico’s reaction to this story.