Now, I haven't verified this at all, but here's an interesting link for you: Ankit Fadia / Manu Zacharia - "Network Intrusion Alert" Heavily Plagiarized.
An extremely detailed analysis has been performed for the first chapter (10 pages) to show the scope and method of plagiarism. Our analysis shows that roughly 90% of the first chapter, including the six graphics used, has been taken from other sources. Due to time constraints, notes are used for brevity for the rest of the material.
Given my experiences with plagiarism among my undergraduate students and the recent Cooks Source plagarism story (which attracted quite a lot of attention)... I'm sadly inclined to believe that this entire book may be plagiarized.
What's funny about this story is that the book in contention here is titled "Network Intrusion Alert: An Ethical Hacking Guide to Intrusion Detection." Emphasis mine.