If you've ever wondered, "whither wiretap?", then you must read this new book, a successor to "Privacy on the Line". In a world of cell phones and Skype, post 9/11, how is US law enforcement changing its communications interceptions? This is a murky world, built around a patchwork of legislation addressing a shifting technological world, and Susan Landau has drawn on extensive public and confidential resources to explain it for the layman.

Landau's well-researched writing is a superb resource for the citizen who wants to be an informed participant in the civil rights debate that is succinctly summarized in the title. The technology of the Internet, which has moved from being data on a voice network to carrying voice on a data network, is integral to the new world of surveillance, and the book has clear descriptions of the architecture, its security (or non-security) history, its vulnerabilities, and the challenges it presents for wiretap.

In the new world of wiretap, the government has moved aggressively into massive fiber optic data capture, automated remote Internet packet interception, and deep packet inspection. You might ask, "Aren't court orders required?", and the answer is "yes", but the devil is in the details, and Landau is a skilled guide through the thicket of the legalties, both in theory, and, fascinatingly, in some examples of practice outside the legalities.

There are fundamental questions surrounding the utility of surveillance, and Landau examines many of them, based on interviews, documents, and court decisions. How effective are the wiretap technologies in achieving their ultimate aim, the protection citizens from criminal harm? How many wiretaps are being done, is the number increasing as the technology becomes more deeply embedded in the equipment at ISPs? Can Internet surveillance be avoided? What are its successes and failures? Is law enforcement at odds with Internet innovation?

Landau's contribution is as much in how she pursues these questions as in the answers that she has gleaned. Legislation, court documents, industry practices, and discussions with insiders and journalists can be fit together into a logical framework, a timeline, and a set of logical trends. Readers of this book can move forward in developing their own opinions on wiretap using more facts and fewer conspiracy theories.

Does a nation have to sacrifice security for surveillance, or should the question be, does surveillance entail less security? Every technology has its weak points, and automated surveillance may open vulnerabilities that can be exploited by enemies of security. If these questions interest you, there is no better book to read than this.