on september 1, 2013, brazil's globo network revealed the national security agency's spy program directly targeted the communications of president dilma rousseff and her top aides. the story was uncovered by glenn greenwald based on nsa documents leaked by edward snowden. the documents described how the nsa used its computer programs to gain access to e-mails, telephone calls and text messages of rousseff and her aides. on september 2, 2013, rousseff called an emergency meeting with her top cabinet members to discuss the revelations. the u.s. ambassador to brasília, thomas shannon, was summoned to brazil's foreign ministry to explain the u.s. spying. the brazilian government called a press conference to denounce the act as an "unacceptable violation of sovereignty" and to announce it had requested an immediate explanation from the u.s. government.