Related link: http://www.infosecwriters.com/texts.php?op=display&id=117

The article covers the typical mistakes organizations make while while planning and deploying the intrusion detection systems. In addition to the obvious mistake (0th, I guess :-)) of not evaluating and deploying the IDS technology at all, the issues we cover often decrease or even eliminate the added value the companies might otherwise derive from running an intrusion detection system.