Horror stories

I am currently awaiting my first placement and I'm very excited. However, my parents definitely do not share my enthusiasm. My mother is very worried that I'm ruining my life by becoming a foster parent. She tells just about everybody she sees that I'm going to be a foster parent and they all have these horror stories to tell about someone they knew who did foster care and the children made false allegations on them, destroyed the house, were physically abusive, etc. On the other hand, when I have told someone that I'm going to be a foster parent, I've always gotten pretty positive responses (or at least not so negative). Why do you think it is that my mom seems to attract the people with all these horror stories? Anyone have any positive stories about foster parenting that I could share with my mom to ease her mind a bit? She now thinks I'm going to be murdered in my sleep by a foster child.