bell, through the millicent and eugene bell foundation. >> narrator: the biggest leak of government secrets ever began in december of 2012 with a single email delivered to an ip address in rio de janeiro. >> glenn greenwald, one of the world's busiest journalists, is sitting in his home in rio, and he sees an email from someone he doesn't know-- it's not a friend, it's not his mom-- and it just says, "i've got some stuff you might be interested in." >> he didn't use his name, and he said very cryptically and very vaguely that he had information that he wanted to discuss with me, but could only do so if i were to install encryption. >> narrator: guardian newspaper columnist and blogger glenn greenwald didn't pay much attention to the email. >> 99% of the time, it ends up that they're crazy or delusional, or the story is just not very good. >> and this guy or girl-- we don't know who it is-- is persistent, so a few days later emails again and says, "look, glenn, can you do this thing?" and glenn still doesn't do it. this attempt, basically,