It is partly the breed, but mostly the owner. If the worst criminal on earth let their three pound Chihuahua run loose - what could it do? But it is more an owner problem than a breed or even general dog problem for sure. Any breed can be mean and any breed can be the most stable, sweet dog on earth. Breed bans will never work, because criminals and other "tough dog" lovers/irresponsible people, will just move on to the next one. People just need to keep their dogs under control, period. I have three and am a lifelong dog lover/breeder/fancier, but I don't appreciate other people's dogs destroying my property or threatening my family.
Keep calling AC. Sometimes it is the particular AC officer that gets the report that matters. Sometimes it's just the squeaky wheel. We had a problem with our neighbor's dogs (Rottweiler and Pit mix, just for the record) coming in our yard and growling at us - including our then eight year old daughter. The first time I called AC, they told me to just work it out with my neighbor. Yeah right. The second time, I think they called the neighbor and told them to keep their dogs out of my yard, but didn't even write it up in their records. The third time, a new officer came out to our house, took a written report, asked me to take photos (which I already had) and went to visit our neighbor. When he tried to deny the dogs were over here, she told him "don't even try it, I've got pictures." She also told us to shoot the dogs if they threatened us and if they came back over, she could confiscate them. They kept the dogs up for about three months and then the Rottie was back over here, growling at us again in our own driveway. My husband is way too nice and sent them a letter, with a copy to the HOA president, stating what AC told us regarding shooting his dogs or confiscating them and putting them down. They finally put up a fence and those dogs haven't been back over here in almost a year now. Of course the neighbors don't speak do us now and have bad mouthed us to other neighbors, but at least my child is safer and any neighbors I care about or that have any sense are on my side anyway. If you have a leash law or dangerous dog law or even a nuisance dog law, AC needs to be made to enforce it.