Rear Window (1954)
The film doesn't question whether spying on the neighbors is defendable, Hitch is stating the obvious: if we were in Jeffries' situation, we would watch. Besides, as sitting viewers, aren't we living metaphors of Jeffries' condition? The movie tackles and tickles this aspect of voyeurism, mirrored by the French saying 'when I see myself, I feel bad, when I see the others, I feel better'. Like Jeffries, we're even more voyeurs because it allows us to ignore our own flaws and responsibilities, a defensive mechanism brilliantly illustrated by the two female characters who indirectly highlight Jeffries' weaknesses and loopholes... which we would notice... if we weren't so busy watching what he watches.