What an amazing film. A man, so good at his job of wiretapping/electronic spying [this was filmed in 1974, mind you], yet paranoid about his own privacy and security. Gene Hackman was brilliant in his subtle, natural mannerisms. He's good in everything, IMO.
All the actors were excellent, well
-cast. The sound, the direction, the subtle background music-- just perfection. It was an interesting puzzle to piece together, hearing the tapes played repeatedly, with more revealed by the film's finale. Interesting use of how we LISTEN selectively to what people are really saying.
I don't want to give away any spoilers, just watch it. People who complain that it is too slow-moving are spoiled by having everything spelled out for them simplistically in mediocre movies and television. It's fun to use one's brain!