Robert "RSnake" Hansen is the author of 'Detecting Malice' book and the ha.ckers.org web application security lab. He has spoken at industry conferences around the world and is widely considered to be a security hyena, although some consider him an expert in web application security. Much of the controversy has come from him hyping up bad html as a vulnerability known as "clickjacking" and for calling out Tavis Ormandy to be fired for releasing exploit code (because the right to free speech is ridiculous)