I've been going through this with my dog, if she was a lot smaller I'd say she was a yappy terrier. She thinks the street is her domain and will bark at anyone who enters it. It's only in the last few days she seems to have got the idea that people can be in the street and neighbours gardens without her having to bark (I've had her almost 3 years now and she's always done thins). I had tried everything I could think of and gone back to basics several times all with no success. I posted on here and was offered some really good advice, we went back to basics once again and suddenly when she was told quiet she actually stopped barking and didn't bark at a stranger after being told quiet. She barked at someone in my neighbours garden today and I told her quiet and she stopped again. It is possible to stop this behaviour and I'm not sure what the magic was with Katie as like I've said I tried everything several times but suddenly something has obviously clicked in her brain and she now understands what is expected of her. Good luck and I'm sure the kind people on here will be able to offer you lots of advice.