On May 30, Reuters quoted the Danish radio and television station as saying that the US National Security Agency (NSA) used its cooperative relationship with the Danish intelligence agency to secretly monitor the leaders of European allies, including German Chancellor Merkel and other European governments. High-ranking officials. Once the blockbuster was detonated, the whole world was blown up. How was this exposed? Let's start with the "Prism Gate" incident. As early as June 2013, Snowden exposed to the media a large-scale secret surveillance project code-named "Prism" in the United States. According to documents provided by Snowden to the Guardian, the agency had censored at least 200 Telephone numbers were monitored, including those of leaders of many countries.