We haven't had that problem with Jack because he's still a puppy and just haven't had him out much. But we used to get that with our english mastiff who was 170 lbs. Max was a big sweetheart and even bigger couch potato. He'd only hurt you if he stepped on your foot. But everyone was afraid of him. I'm guessing if you don't know the breed, the look can be intimidating. As a parent to small children though, I'm teaching them to never run up to a dog that they don't know regardless of the breed. I'm teaching them that they need to ask permission before approaching a dog and how to hold out a hand to let the dog sniff first.