People-look at the YouTube video I have posted here. What is this guy trying to accomplish with his Rottie? As the dog snarls aggressively, the man is rubbing and petting and positively reinforcing the growling. It seems the dog is growling at the person who is taking the video and the man holding and petting the dog is trying to keep it from attacking, but in my mind, as a pet owner and lawyer focusing much of my practice on dog bite and attack cases, this looks like the guy is accidently reinforcing the aggressive behavior by rewarding it with affection. The dog obviously is devoted to the man petting it and would probably kill to protect him. Dogs are protective enough and do not need to have this kind of behavior rewarded. Not a good idea.
The next time this videographer happens to be alone with that Rottweiler who knows what it will do? These people are asking for trouble. If you have a dog that exhibits this type of conduct, get suggestions from your vet on how to stop the behavior. If you feel you cannot afford a professional trainer, get a good book on dog training and watch Dog Whisperer-no kidding. What would Caesar Milan do here? Not this!