Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Caution !

I agree with the people who say this book might get you hurt. The techniques to me look too dangerous. There is one picture that shows a gun being pulled, and the next picture, the defender has the gun (voila !!). No picture intermediate to that explains HOW the defender got the bad guy's gun. I find this book actually kind of funny. If you really want effective self defense, sign up for krav maga in your area. Brazilian jujitsu is a SPORT martial art, not a street martial art. Do you want to take a rabbit rifle to a bear hunt ? Me either. Also, no real knife attacker will make it so easy that you can do the defenses in this book. He already has your "defenses" thought through, and how he will answer them. Real knife fighers do feints and don't let you see the knife, or they will draw you one way and slash back. This book answer none of those questions, as far as I am concerned.