Quoted from "e-Discovery For Dummies"
by Linda Volonino and Ian Redpath
Wiley Publishing, Inc. © 2010
"Imagine having 200,000 documents stacked in front of you and trying to find two documents that may be confidential or privileged. This needle-in-the-haystack scenario is a common occurrence, and the haystack is getting bigger. On television,
cases get finished up within an hour — unless the show is a miniseries; then it may take as long as four hours. The reality* is that the e-discovery process can take years."
The central words are "needle-in-the-haystack".