I found this book a little strange at first, as there didn't seem to be a point. Each chapter starts out with an explanation of how something works (TCP, for instance). Then where there are holes in the implementation or spec, then how the holes can be exploited to learn things in unexpected ways.
The book certainly isn't comprehensive in its chapter reviews of any of the technologies or their flaws. But it dawned on me slowly that completeness wasn't the point. Instead, the book was trying to point out a certain way of looking at things, a 'learning to be sneaky' mentality. By the end of the book, I was hooked. The mindset could apply to project planning, contract writing, just about anything where there are rules to be followed.
I give this book a 7 out of 10 for an interesting read.