And, remember, this isn't a direct attack on you and your dogs. This letter went out to everyone in your neighborhood and was a direct result of bad pet management by the golden retriever owner. (and I am completely shocked that a Golden would cause such horrible damage to a child. I've never met a golden who was anything but gentle and sweet).
Apparently this is happening with Goldens more and more now due to popularity and bad breeding practices. It's so sad because they are the most wonderful dogs, and all of a sudden now I've heard tons of stories about them biting and attacking.
Lin, I'm sorry that you're so upset. I've been there with Homeowner's Associations and big dog prejudice. Sadie is one of three large dogs in our neighborhood and she doesn't even get the brunt of it anymore. Our neighbor's GSD gets tons of complaints and it is by far the best behaved dog in the neighborhood. I would do as others have suggested. Find lots of stories about Rotts doing good things, rescue, police work, whatever you can find.
Also try not to get defensive, as hard as that is. That was my biggest mistake with my neighbor situation. Your dogs have done nothing wrong, there's no legal way that I know of for anyone to force you to do anything. They can't force you to get rid of your dogs or chain them up or anything like that because SOME Rottwielers have bitten people. The best thing you can do at this point is educate your neighbors about the breed and your dogs in particular. Things like this ALWAYS stem from fear and from ignorance. If you stay calm and show them there's nothing to be afraid of with your girls, everything will be ok. I'm sure of it. Should you HAVE to do that? No, absolutely not. It's not fair that you should have to defend your dogs because of something another dog (in this case it's not even the same breed, just roughly the same size!) did. But people start things like this up because they are scared and they don't know any better. If events like Goldens attacking people show us anything it is that you can NEVER judge a dog solely based on it's breed - good or bad.
If you need anything, let us know. I'd be more than happy to help you research or something. If nothing else, just take comfort in the fact that BPO's got your back girlfriend