My best friend had one - that little dog dominated him, and made his life miserable. Anytime he left, the dog would tear up something. Ate a few couches, all of his cds, movies, his bed, etc. You couldn't call him on the phone at his house because as soon as he tried to talk, the dog would get close and bark every single time he'd open his mouth to talk. It was kind of funny - you'd call and tell the guy what you wanted to say in silence, but as soon as you could tell he was gonna say something, the dog would bark. He could not get one word out. If he tried to go in another room and talk, the dog would start tearing s*** up.
My friend is a pretty mellow dude, but I'd be damned if I would let a dog walk all over me like that one did to him. He used to catch a bunch of grief about it, too. If he showed up at one of our houses with that dog, we'd tell him to leave. He'd be like "c'mon guys, he's not that bad. I just can't leave him home alone..."
He bought the thing from a puppy mill, and unfortunately for the dog (but fortunately for him) his aorta ruptured when he was about two years old. I hated that dog, but wouldn't hold it against the breed because of a s***ty owner ill prepared to have a high energy intelligent dog like that.