I might as well post on this topic - I was staying away from it, but what the heck, might as well...
I live alone. I'm small, female, and I live in an apartment, in a college town (I have to... I'm going to college!). My SO does not live with me, as he is going to college elsewhere.
I have two Dobermans. They are pets first and foremost, but they are also my protectors - and have proven themselves in this regard.
Situation #1: Someone robbed a neighboring house, and was caught in the act - he ran. He saw my family's house, and decided that it looked like a great place to hide... but Ilsa disagreed. She cornered that criminal in our living room, backed him into a corner - until the police arrived to arrest him. What could have happened if Ilsa hadn't been there? Would he have seen me (I was alone in the house) and ran away? Would he attack me? Luckily we didn't find out, thanks to my Doberman.
Situation #2: I was biking, late at night. I'm a full time student and also hold a nearly full-time job, so that was the only time that day I could get out and exercise. I had brought Ronin with me. About midway through the ride, a man ran at my bike from the darkness, and tried to push me off my bike. Ronin swung around (I accidentally hit him square int he chest with my bike in the process), let out a roar, and nearly took the guy's face off. He yelled something like, "Sh*t, I didn't know you had a DOG!" and ran off. What would he have done if my Doberman hadn't been with me - would he have pushed me off my bike, laughed, and went on his merry way? Would he have robbed me? Would he have raped me? Thanks to my Doberman, we didn't have to find out.
Situation #3: I was in the bathroom, both dogs were loose in the apartment. My sliding glass door was open, because my SO was coming over and he doesn't have a key (my landlord only issues one key per tenant, and I'm the only tenant). Someone walked into my apartment... but it wasn't my SO. It was a stranger - my dogs immediately backed him into a corner, snarling and barking. I came out to see what the ruckus was, and found this *strange man* in my apartment! I asked him what the heck he was doing there, and he made some lame excuse as to why he'd walked into my apartment without knocking. I told him to leave, and told my dogs to let him go... and instead of backing outside, the guy took a quick step toward me. Ronin leapt forward and again, nearly took the guy's face off. If I hadn't been holding tight to his collar, he would have bitten the intruder. Now... if it hadn't been for my protectors, what would that guy have done? Would he have robbed me? Would he have raped me? Would he have killed me? Luckily, my Dobermans saw to it that I didn't have to find out the hard way.
It's easy for people who either live with their spouses or parents to say there's no need for this young woman (BlackDog) to have a dog that can protect her. But I'm in her shoes - I share her situation - and if it wasn't for my dogs, dogs that have proven that they're ready and willing to bite the bad guys - I might not be here to be typing this.
Luckily, my dogs aren't attacking machines - they are bold enough to back a bad guy into a corner and HOLD him there - I can't think of many
watchdogs that have the courage to hold an aggressor for more than a few seconds. In both holding situations, the dogs held the bad guy in a corner for more than 1-2 minutes before I came to investigate.