I purchased and read this entertaining romp despite having skimmed it at the bookstore and reading this poor ad hominem argument:
"After watching the way the worldwide media and the international community reacted to the question of Iraq's weapons of mass destruction, I don't think they'd see a smoking gun if you stuck it right against their foreheads." (p. 220)
I purchased it anyway, because although I think that's an incredible feeble aside (Mr. Ranum doesn't bother to say what smoking guns he thinks have been established, and it seems clear as of this writing that there are no WMDs in Iraq, and no good evidence that there were any post-1994), elsewhere in my initial skimming I saw what looked to be very interesting information about the Homeland Security Act and the USA PATRIOT Act. Largely because of this material, I did find the book to be worth my time (if not quite worth the dollars I spent on it--I should have waited for a paperback edition).
The book is definitely a polemic, not a researched and referenced scholarly tome--there are no references or footnotes, beyond the suggested further reading material on pp. xvi-xvii. There is much to disagree with besides the above example, as other reviewers here have noted. It's short on conclusions and suggested remedies, though there are a few radical (i.e., politically impossible) suggestions, such as abolishing the INS and starting over from scratch (probably not a bad idea at all).
I recommend it for those interested in a lightweight, quick read to get a quick overview of the problems of securing an entire nation and the means that are being adopted with that alleged goal, but if you are looking for depth and detail, with solidly argued conclusions and recommendations, you'll need to look elsewhere.