Beginning in May 2010, the NSA gained access to the Mexican Presidencia domain on the Mexican Presidential network and began monitoring then-president Felipe Calderon's email account, according to a document leaked to Der Spiegel by Edward Snowden. The document also shows that the NSA has been surveilling the Brazilian government.
Hacking the Mexican presidential email was part of a campaign called "Flatliquid," which provided U.S. cabinet members with "diplomatic, economic and leadership communications which continue to provide insight into Mexico's political system and internal stability," according to the document obtained by Spiegel.
This revelation about NSA hacking may, not surprisingly, lead to increased tension between the U.S. and Mexico. Relations were already strained by a report aired on Brazil's TV Globo network indicating that the NSA had done surveillance in the summer of 2012 on Mexico's current president, Enrique Peña Nieto, who was running for president at the time.
Informations about the NSA's surveillance in Brazil has also been surfacing in recent months, causing Brazil's president, Dilma Rousseff, to cancel a Washington D.C. visit a few weeks ago and deliver an extremely critical speech at the UN General Assembly. [Der Spiegel via Slashdot]