How can so many entries be analyzed?

Saw a great quote in an article on data analysis that noted to review 100,000 journal entries at a client would take close to 1,000 person days to audit.

While maybe not that large, if you think it through, most mid-sized companies have at least 5,000 journal entries and probably 250,000 lines to these entries. Without a computer, how could these be reviewed effectively from an audit or fraud detection perspective?

Food for thought and comments are welcome,
Rich Lanza