Mine was quite bad for it when he was younger while walking down the street, never kids or groups just people on their own. Sometimes it lead to barking at them when they startled him getting out of cars or out of driveways etc.
He's protective of the house and my family especially when I'm not there and I'm pretty sure he would bite an unwelcome intruder which to me isn't a bad thing. He won't be getting pinched in a hurry anyway.