National Security Agency leaker Edward Snowden wrote in a lengthy open letter to the people of Brazil" that he has been inspired by the global debate ignited by his release of thousands of documents and that the NSA's culture of indiscriminate global espionage "is collapsing." In the letter, Snowden commended the Brazilian government for its strong stand against U.S. spying. He wrote that he would be willing to help the South American nation investigate NSA spying on its soil but could not fully participate in doing so without being granted political asylum, because the U.S. "government will continue to interfere with my ability to speak." The documents revealed that Brazil is the top NSA target in Latin America, in spying that has included the monitoring of Brazilian President Dilma Rousseff's cellphone and hacking into the internal network of the state-run oil company Petrobras. In his letter, Snowden dismissed U.S. explanations to the Brazilian government and others that the bulk metadata gathered on billions of e-mails and calls was more "data collection" than surveillance. "There is a huge difference between legal programs, legitimate spying ... and these programs of dragnet mass surveillance that put entire populations under an all-seeing eye and save copies forever," he wrote. "These programs were never about terrorism: they're about economic spying, social control, and diplomatic manipulation. They're about power." Brazilian senators have asked for Snowden's help during hearings about the NSA's targeting of Brazil, an important transit hub for transatlantic fiber-optic cables that are hacked.