vietnam war. this weekend, msnbc is presenting a special documentary, the most dangerous man in a america, a real-life thriller about daniel elsberg, the man who leaked the classified documents and changed history. >> i began xeroxing the mcnamara study in the fall of 1969. at the end of the day working at rand, i would put several volumes into my brief case to take with me. walking past the security guards, i could feel my heartbeating. i couldn't help thinking about the dozen or so secrecy agreements i had signed over the course of my career in government. the task seemed endless. i often worked through the night. early in the morning, i returned the papers to my safe at rand and headed home.