A wiretap expert spies on a couple he suspects will be murdered, in the movie The Conversation. Features an amazing performance by Gene Hackman as Harry Caul. Written and directed by Francis Ford Coppola, it’s a Roger Ebert 4-star movie:

"Coppola, who wrote and directed, considers this film his most personal project. He was working two years after the Watergate break-in, amid the ruins of the Vietnam effort, telling the story of a man who places too much reliance on high technology and has nightmares about his personal responsibility. Harry Caul is a microcosm of America at that time: not a bad man, trying to do his job, haunted by a guilty conscience, feeling tarnished by his work."