Glenn Greenwald, the journalist who helped NSA leaker Edward Snowden expose state secrets to the world, is set to make his “biggest” disclosure yet — the names of Americans the government spied on, he told The Sunday Times.Greenwald added that Snowden’s legacy will be “shaped in large part” by this “finishing piece,” which is based on information obtained in the nearly 2 million documents the former NSA contractor secretly stole from the government.