This book does not start off well, since the author does not have a very good grasp of the technology. The cases she presents early in the book are familiar, but are described without nuance and with the FUD turned up to 11. I almost quit reading, I was so frustrated. I question her definition of a "website" and "social media" (neither of which she gives a clear definition in the text, though obviously there is a difference in her mind). Furthermore, she thinks that everyone has two distinct lives: offline and an online "doppelganger" (see my earlier comment on FUD). Only two? She should do more reading on publics.
Once the book moved away from the technical and into the legal it became much more palatable and possibly even interesting. I assume as she is a lawyer, her grasp of the legal aspects of her argument are better than the technical. She presents an astonishing number of cases which makes me suspect she is glossing over any nuance like she did when she talked about technical topics… but not being a legal scholar I cannot tell.
There certainly is an information management problem exacerbated by the web. I doubt if the solution is a "Social Media Contract" as proposed in this book. At least, the current laws need to be updated/generalized to include online aspects.
This book is short and might serve as a (alarmist) primer. My advice is read it quickly and don't stop here.