You'd want to keep some of those people around though. Computers are great for detecting anomalies and known patterns but you need the human brain to invent new patterns to look for.

Of course, sometimes a brain will invent a really weird pattern. You get agriculturally incompetent aliens, government employed blues brothers fans and all kinds of nonsense. I guess that's why intelligence gathering should be done in a group. More eyes results in less errors, right? :)