Arif - they get a bad reputation! These dogs are protective yes, but not mean if they've not been treated meanly! If they're a family pet, they're ok! I've known several! When I was growing up in Detroit, the neighbor got one to protect his house and give him a sense of being tough, he was afraid of his own dog and kept it chained in the yard. Us kids noticed he didn't have enough water so we went over with a dog treat, and gave him water and let him off the chain and played with him in his yard...when the owner came home he was furious because here was his "vicious" dog playing with neighborhood children, and he couldn't get close to the poor thing!
However, definitely agree that they're protective especially at night!